1. Chronic diseases have more drastic long-term effects on health compared to acute diseases. While acute diseases resolve quickly, chronic diseases persist for a long time or lifetime, reducing ability to function physically, mentally and socially over years.
2. Diseases can have multiple levels of causes, from immediate causes like infectious agents or viruses, to contributory causes like poor nutrition or lack of access to clean water. The immediate cause may be necessary but not sufficient on its own to cause disease without additional contributory social and environmental factors.
3. Causes of diseases can be infectious, spreading between individuals through microbes, or non-infectious, arising from internal factors like genetics rather than external transmission. The nature of
Chapter - 13, Why do we fall ill, Science, Class 9Shivam Parmar
Â
I have expertise in making educational and other PPTs. Email me for more PPTs at a very reasonable price that perfectly fits in your budget.
Email: parmarshivam105@gmail.com
Chapter - 13, Why do we fall ill, Science, Class 9
HEALTH
FACTORS THAT DETERMINE BETTER HEALTH
WHAT DO YOU MEAN BY A DISEASE?
DISEASE - FREE DIFFERENT FROM BEING HEALTHY?
HOW CAN WE STAY DISEASE FREE?
HOW CAN WE IDENTIFY A DISEASE?
ACUTE DISEASES AND CHRONIC DISEASES
FACTORS CAUSES DISEASES?Â
CAUSES OF DISEASE
INFECTIOUS AND NON-INFECTIOUS CAUSES OF DISEASE
INFECTIOUS AGENTSÂ
SEVERAL TYPES OF DISEASES
INFLAMMATION
PRINCIPLES OF TREATMENT
ANTIBIOTICS AREN’T EFFECTIVE AGAINST VIRUSES?
PRINCIPLES OF PREVENTION
WHAT IS THE IMMUNE SYSTEM?
Every topic of this chapter is well written concisely and visuals will help you in understanding and imagining the practicality of all the topics.
By Shivam Parmar (Entrepreneur)
Health is defined as a state of complete physical, mental, and social well-being, allowing one to have a positive outlook and cope well with stress. Disease impairs the normal functioning of the body and is a response to various environmental, infectious, or inherited factors. There are two main types of diseases: those present since birth due to genetic or organ abnormalities, which are generally permanent and inheritable; and acquired diseases after birth, which include infectious diseases spread between people or non-infectious diseases due to dietary or tissue degeneration issues.
This document discusses diseases and health. It defines health as a state of physical, mental and social well-being, and disease as any disturbance in the structure or function of the body. It describes different types of diseases like acute, chronic, congenital and acquired diseases. It explains infectious diseases in detail, including the infectious agents (viruses, bacteria, fungi etc.), means of spread, organ-specific manifestations, and principles of treatment and prevention. It emphasizes that classifying diseases based on their infectious agents is important for deciding appropriate treatment since members of the same group (e.g. bacteria) often respond similarly to drugs.
The document discusses the causes of diseases. It states that some diseases are caused by bacteria while others like AIDS and the common cold are caused by viruses. Normally our immune system protects us but sometimes due to lack of sleep, stress or poor nutrition, our bodies become weak and susceptible to disease. Vaccines can help prevent some diseases by strengthening our immunity. The document then discusses different types of diseases like infectious, contagious, airborne diseases and non-communicable diseases. It also talks about lifestyle diseases and gives examples of bacterial and viral diseases.
This document discusses why we fall ill and covers several topics related to health and disease. It defines health and its failure, explores personal and community questions for health. It distinguishes between being healthy and disease-free. It examines disease and its causes, including acute vs. chronic disease. It looks at infectious vs. non-infectious disease and various infectious agents. It discusses means of disease spread and examples. Finally, it outlines principles of treatment and prevention, including vaccination.
This document discusses various aspects of health and disease. It defines health as a state of complete physical, mental and social well-being. Maintaining good health requires a balanced diet, exercise, proper shelter, sleep and hygiene. Disease can be caused by intrinsic or extrinsic factors and can be acute, chronic, congenital or acquired. Infectious diseases spread via air, water, food, vectors or contact and common examples are provided. Prevention focuses on avoiding exposure and immunization, while treatment aims to reduce symptoms and kill microbes. Vaccination helps strengthen immunity against specific diseases. The main pathogens that cause infectious disease are viruses, bacteria, fungi, protozoa and worms.
This document discusses health and disease. It defines health as a state of complete physical, mental and social well-being. Good health depends on factors like a healthy environment, economic conditions, and social harmony. Diseases are caused by pathogens, genetic disorders, pollution, and malnutrition. Diseases can be acute, chronic, infectious, or non-infectious. Infectious diseases spread through contact with infected individuals, while non-infectious diseases do not. The document outlines various infectious and non-infectious diseases and how they are transmitted. It also discusses principles of treatment and prevention of infectious diseases.
- The document discusses the causes and types of diseases. It explains that health depends on physical, social, economic, and environmental factors as well as personal hygiene. Diseases are caused by infectious agents like viruses, bacteria, fungi, and parasites or non-infectious factors like genetics.
- Infectious diseases can be transmitted through air, water, vectors, or sexual contact and affect different organs depending on the point of entry. Treatment involves reducing symptoms and killing microbes while prevention focuses on public hygiene, immunization, and strengthening immunity through vaccines.
Chapter - 13, Why do we fall ill, Science, Class 9Shivam Parmar
Â
I have expertise in making educational and other PPTs. Email me for more PPTs at a very reasonable price that perfectly fits in your budget.
Email: parmarshivam105@gmail.com
Chapter - 13, Why do we fall ill, Science, Class 9
HEALTH
FACTORS THAT DETERMINE BETTER HEALTH
WHAT DO YOU MEAN BY A DISEASE?
DISEASE - FREE DIFFERENT FROM BEING HEALTHY?
HOW CAN WE STAY DISEASE FREE?
HOW CAN WE IDENTIFY A DISEASE?
ACUTE DISEASES AND CHRONIC DISEASES
FACTORS CAUSES DISEASES?Â
CAUSES OF DISEASE
INFECTIOUS AND NON-INFECTIOUS CAUSES OF DISEASE
INFECTIOUS AGENTSÂ
SEVERAL TYPES OF DISEASES
INFLAMMATION
PRINCIPLES OF TREATMENT
ANTIBIOTICS AREN’T EFFECTIVE AGAINST VIRUSES?
PRINCIPLES OF PREVENTION
WHAT IS THE IMMUNE SYSTEM?
Every topic of this chapter is well written concisely and visuals will help you in understanding and imagining the practicality of all the topics.
By Shivam Parmar (Entrepreneur)
Health is defined as a state of complete physical, mental, and social well-being, allowing one to have a positive outlook and cope well with stress. Disease impairs the normal functioning of the body and is a response to various environmental, infectious, or inherited factors. There are two main types of diseases: those present since birth due to genetic or organ abnormalities, which are generally permanent and inheritable; and acquired diseases after birth, which include infectious diseases spread between people or non-infectious diseases due to dietary or tissue degeneration issues.
This document discusses diseases and health. It defines health as a state of physical, mental and social well-being, and disease as any disturbance in the structure or function of the body. It describes different types of diseases like acute, chronic, congenital and acquired diseases. It explains infectious diseases in detail, including the infectious agents (viruses, bacteria, fungi etc.), means of spread, organ-specific manifestations, and principles of treatment and prevention. It emphasizes that classifying diseases based on their infectious agents is important for deciding appropriate treatment since members of the same group (e.g. bacteria) often respond similarly to drugs.
The document discusses the causes of diseases. It states that some diseases are caused by bacteria while others like AIDS and the common cold are caused by viruses. Normally our immune system protects us but sometimes due to lack of sleep, stress or poor nutrition, our bodies become weak and susceptible to disease. Vaccines can help prevent some diseases by strengthening our immunity. The document then discusses different types of diseases like infectious, contagious, airborne diseases and non-communicable diseases. It also talks about lifestyle diseases and gives examples of bacterial and viral diseases.
This document discusses why we fall ill and covers several topics related to health and disease. It defines health and its failure, explores personal and community questions for health. It distinguishes between being healthy and disease-free. It examines disease and its causes, including acute vs. chronic disease. It looks at infectious vs. non-infectious disease and various infectious agents. It discusses means of disease spread and examples. Finally, it outlines principles of treatment and prevention, including vaccination.
This document discusses various aspects of health and disease. It defines health as a state of complete physical, mental and social well-being. Maintaining good health requires a balanced diet, exercise, proper shelter, sleep and hygiene. Disease can be caused by intrinsic or extrinsic factors and can be acute, chronic, congenital or acquired. Infectious diseases spread via air, water, food, vectors or contact and common examples are provided. Prevention focuses on avoiding exposure and immunization, while treatment aims to reduce symptoms and kill microbes. Vaccination helps strengthen immunity against specific diseases. The main pathogens that cause infectious disease are viruses, bacteria, fungi, protozoa and worms.
This document discusses health and disease. It defines health as a state of complete physical, mental and social well-being. Good health depends on factors like a healthy environment, economic conditions, and social harmony. Diseases are caused by pathogens, genetic disorders, pollution, and malnutrition. Diseases can be acute, chronic, infectious, or non-infectious. Infectious diseases spread through contact with infected individuals, while non-infectious diseases do not. The document outlines various infectious and non-infectious diseases and how they are transmitted. It also discusses principles of treatment and prevention of infectious diseases.
- The document discusses the causes and types of diseases. It explains that health depends on physical, social, economic, and environmental factors as well as personal hygiene. Diseases are caused by infectious agents like viruses, bacteria, fungi, and parasites or non-infectious factors like genetics.
- Infectious diseases can be transmitted through air, water, vectors, or sexual contact and affect different organs depending on the point of entry. Treatment involves reducing symptoms and killing microbes while prevention focuses on public hygiene, immunization, and strengthening immunity through vaccines.
This document summarizes the causes and types of diseases. It discusses that health involves physical, mental, and social well-being, while disease is a state of poor health. Diseases can be acute, chronic, infectious, or non-infectious. Infectious diseases spread through various means like air, water, food, vectors, physical contact, or sexual contact. The causes of diseases include pathogens, poor health, environmental pollution, and genetic disorders. The document also discusses the treatment and prevention of infectious diseases.
This document provides information about different types of diseases including infectious and non-infectious diseases. It discusses how diseases spread and are transmitted through various modes such as contaminated food/water, vectors, direct contact, and more. Specific examples of diseases caused by viruses, bacteria, and other microorganisms like malaria, influenza, rabies, AIDS, cholera, and typhoid are described along with their symptoms, prevention, and treatment methods. The document aims to educate about health, different disease conditions, and the importance of hygiene and sanitation in preventing the spread of illnesses.
Powerpoint Presentation of Why Do We Fall Ill? is a presentation about health, diseases, types of diseases, and list of 5 main diseases.
Hope you LOVE it!!!!!!!!!!!!
There are two main types of diseases: acute and chronic. Acute diseases like the common cold last for a short period of time, while chronic diseases like tuberculosis can last a lifetime. Infectious diseases are caused by pathogens and can be transmitted from person to person, while non-infectious diseases are not caused by pathogens. Infectious diseases spread through various means such as air, water, sexual contact, or vectors. The pathogens that cause diseases include viruses, bacteria, fungi, protozoa, and worms. Treatment focuses on reducing disease effects and killing the microbes causing the disease.
Good health requires a good physical and social environment, good economic conditions, and social equality and harmony. When a person falls ill, their normal bodily functions or appearance change for the worse, resulting in symptoms. Doctors examine these symptoms to identify the disease and conduct tests to confirm the diagnosis. Diseases can be acute and short-term, chronic and long-lasting, infectious and spread between people, or non-infectious. They are caused by pathogens, poor nutrition, bodily malfunctions, environmental pollution, or genetic disorders.
The document discusses various topics related to health and disease. It defines health as a state of complete physical, mental and social well-being. It discusses factors that influence personal and community health, such as hygiene, sanitation, socioeconomic conditions, and health education. It also defines and compares acute and chronic diseases, communicable and non-communicable diseases, and discusses various causes of diseases like viruses, bacteria, fungi, and parasites. The document also discusses the immune system and process of immunization to build immunity against diseases.
(1) The document discusses causes, types, spread, and prevention of diseases. It explains that diseases are caused by pathogens like viruses and bacteria, genetic disorders, environmental pollution, and malnutrition.
(2) Diseases are classified as acute or chronic, infectious or non-infectious. Infectious diseases spread through air, water, food, physical contact, sexual contact, or vectors like mosquitoes and flies.
(3) Prevention of infectious diseases involves public hygiene, access to safe drinking water and food, vaccines, and strengthening the immune system through vaccination.
This document discusses why people fall ill and the causes of disease. It explains that disease can be caused by both intrinsic/internal factors like genetic disorders as well as extrinsic/external factors like unhealthy environments and infectious microorganisms. Communicable diseases can be passed between individuals while non-communicable diseases cannot. Treatment aims to reduce symptoms and kill microbes, while prevention focuses on public hygiene, immunizations, and strengthening the immune system.
This is an Embedded version of the presentation. This Presentation is Updated with some new graphics and interiors,it will help everyone to understand the lesson "Why do we fall ill".
The document discusses diseases, their causes, symptoms, classifications, and prevention. It defines disease and differentiates between healthy and diseased states. Diseases can be acute or chronic based on duration, and infectious or non-infectious based on transmission. Causes include infectious agents, parasites, contaminated food/water, direct contact, or blood transmission. Symptoms depend on the affected organ and include local or general effects. Prevention focuses on reducing symptoms, killing causes through targeted medicines, and general hygiene or vaccination.
The document discusses the conditions necessary for good health, which include a good physical and social environment with clean surroundings, sanitation, clean drinking water, and job opportunities. It also discusses different types of diseases such as acute, chronic, infectious, and non-infectious diseases. Diseases are caused by pathogens like viruses, bacteria, fungi, protozoans, or worms, as well as poor health, malnutrition, malfunctioning body parts, environmental pollution, and genetic disorders.
Science revision for class 9 why do well fall ill. ch 13Basuraj Patel
Â
This document defines key health-related terms like health, healthy, and disease. It also lists factors responsible for good health such as environment, balanced diet, public cleanliness, and social well-being. The document differentiates between acute and chronic diseases as well as communicable and non-communicable diseases. It names diseases caused by protozoans, bacteria, fungi, and viruses. In the test yourself section, it asks the reader to define terms, name constituents of a balanced diet, and differentiate between disease types and list factors for good health.
This document discusses health and disease. It defines health as a state of complete physical, mental, and social well-being, while illness is defined as the opposite of health and changes the functions of the body. Some key health habits mentioned are a balanced diet, meal routine, hygiene, rest, clean air, and exercise. Infectious diseases are discussed as being contagious or non-contagious, while non-infectious diseases are also mentioned. Common pathogens like bacteria and viruses are identified as causes of diseases.
This document discusses infectious diseases, their causes, symptoms, prevention and control. It describes several bacterial diseases like cholera, typhoid and rabies caused by Vibrio cholerae, Salmonella typhi and rabies virus respectively. Malaria is discussed as a protozoan disease spread by the Anopheles mosquito. Symptoms, prevention through vaccination and sanitation, and treatment options are provided for each disease. The document also differentiates between cure and remission of diseases as well as ways of preventing diseases through public health measures, nutrition and vaccinations.
PowerPoint Presentation :-
Topic - 'WHY DO WE FALL ILL'
Made By - NehaRohtagi1
This PPT will help the students of class -9 to understand the significance of 'HEALTH' and types of diseases, their symptoms, treatment, prevention, vaccination, etc.
The document discusses diseases, their causes, and how they manifest in the body. It defines disease as any physical or functional change that causes discomfort, disability, or impairs health. It describes acute and chronic diseases and their characteristics. Diseases can be caused by infectious agents like viruses, bacteria, and protozoa, or non-infectious internal factors. The document explains that different disease-causing microbes infect specific organs or tissues based on their point of entry, like lungs for respiratory viruses or liver for food/water-borne viruses. Prevention through vaccination and immunization is better than treatment since diseases can spread and be difficult to cure.
good evening
this presentation has short and easy notes on the chapet WHY DO WE FALL ILL! for clas 9 {cbsc}
for any doubts comment or contact at manavsharma367@gmail.com
Differences between healthy and disease free states are described. Healthy refers to overall well-being while disease free only refers to absence of disease. Causes of diseases include pathogens, poor health, organ malfunctions, pollution, and genetics. Symptoms appear when body functions change due to disease. Diseases are classified as acute, chronic, infectious, and non-infectious. Infectious diseases spread via air, water, food, vectors, contact, and sex. Prevention methods include immunization and general hygiene.
Disease is defined as an abnormal condition that affects the structure or function of an organism. Malaria is a mosquito-borne disease caused by Plasmodium parasites. It causes flu-like symptoms like fever and fatigue. Severe malaria from P. falciparum can cause complications like seizures, coma, or death if not treated properly. Malaria is treated with antimalarial drugs and prevented through mosquito control measures like insecticide-treated nets and indoor spraying.
Difference between Personal Health and Community Health class 9 science.pdfTakshila Learning
Â
Difference between Personal Health and Community Health -Personal health is something that can be maintained by an individual and varies from person to person Community health entails enhancing, preserving, and safeguarding the health of the entire community
This document summarizes the causes and types of diseases. It discusses that health involves physical, mental, and social well-being, while disease is a state of poor health. Diseases can be acute, chronic, infectious, or non-infectious. Infectious diseases spread through various means like air, water, food, vectors, physical contact, or sexual contact. The causes of diseases include pathogens, poor health, environmental pollution, and genetic disorders. The document also discusses the treatment and prevention of infectious diseases.
This document provides information about different types of diseases including infectious and non-infectious diseases. It discusses how diseases spread and are transmitted through various modes such as contaminated food/water, vectors, direct contact, and more. Specific examples of diseases caused by viruses, bacteria, and other microorganisms like malaria, influenza, rabies, AIDS, cholera, and typhoid are described along with their symptoms, prevention, and treatment methods. The document aims to educate about health, different disease conditions, and the importance of hygiene and sanitation in preventing the spread of illnesses.
Powerpoint Presentation of Why Do We Fall Ill? is a presentation about health, diseases, types of diseases, and list of 5 main diseases.
Hope you LOVE it!!!!!!!!!!!!
There are two main types of diseases: acute and chronic. Acute diseases like the common cold last for a short period of time, while chronic diseases like tuberculosis can last a lifetime. Infectious diseases are caused by pathogens and can be transmitted from person to person, while non-infectious diseases are not caused by pathogens. Infectious diseases spread through various means such as air, water, sexual contact, or vectors. The pathogens that cause diseases include viruses, bacteria, fungi, protozoa, and worms. Treatment focuses on reducing disease effects and killing the microbes causing the disease.
Good health requires a good physical and social environment, good economic conditions, and social equality and harmony. When a person falls ill, their normal bodily functions or appearance change for the worse, resulting in symptoms. Doctors examine these symptoms to identify the disease and conduct tests to confirm the diagnosis. Diseases can be acute and short-term, chronic and long-lasting, infectious and spread between people, or non-infectious. They are caused by pathogens, poor nutrition, bodily malfunctions, environmental pollution, or genetic disorders.
The document discusses various topics related to health and disease. It defines health as a state of complete physical, mental and social well-being. It discusses factors that influence personal and community health, such as hygiene, sanitation, socioeconomic conditions, and health education. It also defines and compares acute and chronic diseases, communicable and non-communicable diseases, and discusses various causes of diseases like viruses, bacteria, fungi, and parasites. The document also discusses the immune system and process of immunization to build immunity against diseases.
(1) The document discusses causes, types, spread, and prevention of diseases. It explains that diseases are caused by pathogens like viruses and bacteria, genetic disorders, environmental pollution, and malnutrition.
(2) Diseases are classified as acute or chronic, infectious or non-infectious. Infectious diseases spread through air, water, food, physical contact, sexual contact, or vectors like mosquitoes and flies.
(3) Prevention of infectious diseases involves public hygiene, access to safe drinking water and food, vaccines, and strengthening the immune system through vaccination.
This document discusses why people fall ill and the causes of disease. It explains that disease can be caused by both intrinsic/internal factors like genetic disorders as well as extrinsic/external factors like unhealthy environments and infectious microorganisms. Communicable diseases can be passed between individuals while non-communicable diseases cannot. Treatment aims to reduce symptoms and kill microbes, while prevention focuses on public hygiene, immunizations, and strengthening the immune system.
This is an Embedded version of the presentation. This Presentation is Updated with some new graphics and interiors,it will help everyone to understand the lesson "Why do we fall ill".
The document discusses diseases, their causes, symptoms, classifications, and prevention. It defines disease and differentiates between healthy and diseased states. Diseases can be acute or chronic based on duration, and infectious or non-infectious based on transmission. Causes include infectious agents, parasites, contaminated food/water, direct contact, or blood transmission. Symptoms depend on the affected organ and include local or general effects. Prevention focuses on reducing symptoms, killing causes through targeted medicines, and general hygiene or vaccination.
The document discusses the conditions necessary for good health, which include a good physical and social environment with clean surroundings, sanitation, clean drinking water, and job opportunities. It also discusses different types of diseases such as acute, chronic, infectious, and non-infectious diseases. Diseases are caused by pathogens like viruses, bacteria, fungi, protozoans, or worms, as well as poor health, malnutrition, malfunctioning body parts, environmental pollution, and genetic disorders.
Science revision for class 9 why do well fall ill. ch 13Basuraj Patel
Â
This document defines key health-related terms like health, healthy, and disease. It also lists factors responsible for good health such as environment, balanced diet, public cleanliness, and social well-being. The document differentiates between acute and chronic diseases as well as communicable and non-communicable diseases. It names diseases caused by protozoans, bacteria, fungi, and viruses. In the test yourself section, it asks the reader to define terms, name constituents of a balanced diet, and differentiate between disease types and list factors for good health.
This document discusses health and disease. It defines health as a state of complete physical, mental, and social well-being, while illness is defined as the opposite of health and changes the functions of the body. Some key health habits mentioned are a balanced diet, meal routine, hygiene, rest, clean air, and exercise. Infectious diseases are discussed as being contagious or non-contagious, while non-infectious diseases are also mentioned. Common pathogens like bacteria and viruses are identified as causes of diseases.
This document discusses infectious diseases, their causes, symptoms, prevention and control. It describes several bacterial diseases like cholera, typhoid and rabies caused by Vibrio cholerae, Salmonella typhi and rabies virus respectively. Malaria is discussed as a protozoan disease spread by the Anopheles mosquito. Symptoms, prevention through vaccination and sanitation, and treatment options are provided for each disease. The document also differentiates between cure and remission of diseases as well as ways of preventing diseases through public health measures, nutrition and vaccinations.
PowerPoint Presentation :-
Topic - 'WHY DO WE FALL ILL'
Made By - NehaRohtagi1
This PPT will help the students of class -9 to understand the significance of 'HEALTH' and types of diseases, their symptoms, treatment, prevention, vaccination, etc.
The document discusses diseases, their causes, and how they manifest in the body. It defines disease as any physical or functional change that causes discomfort, disability, or impairs health. It describes acute and chronic diseases and their characteristics. Diseases can be caused by infectious agents like viruses, bacteria, and protozoa, or non-infectious internal factors. The document explains that different disease-causing microbes infect specific organs or tissues based on their point of entry, like lungs for respiratory viruses or liver for food/water-borne viruses. Prevention through vaccination and immunization is better than treatment since diseases can spread and be difficult to cure.
good evening
this presentation has short and easy notes on the chapet WHY DO WE FALL ILL! for clas 9 {cbsc}
for any doubts comment or contact at manavsharma367@gmail.com
Differences between healthy and disease free states are described. Healthy refers to overall well-being while disease free only refers to absence of disease. Causes of diseases include pathogens, poor health, organ malfunctions, pollution, and genetics. Symptoms appear when body functions change due to disease. Diseases are classified as acute, chronic, infectious, and non-infectious. Infectious diseases spread via air, water, food, vectors, contact, and sex. Prevention methods include immunization and general hygiene.
Disease is defined as an abnormal condition that affects the structure or function of an organism. Malaria is a mosquito-borne disease caused by Plasmodium parasites. It causes flu-like symptoms like fever and fatigue. Severe malaria from P. falciparum can cause complications like seizures, coma, or death if not treated properly. Malaria is treated with antimalarial drugs and prevented through mosquito control measures like insecticide-treated nets and indoor spraying.
Difference between Personal Health and Community Health class 9 science.pdfTakshila Learning
Â
Difference between Personal Health and Community Health -Personal health is something that can be maintained by an individual and varies from person to person Community health entails enhancing, preserving, and safeguarding the health of the entire community
This document provides a yogic perspective on cancer. It discusses that cancer occurs due to an imbalance in the body's energy system according to yogic teachings. While medical opinions on cancer change frequently, the fundamental physiology and chemistry of the human body has remained the same. From a yogic view, cancer is seen as resulting from an imbalance in the pranamaya kosha or energy body, rather than being different types based on where it manifests. The document advocates gaining a deeper understanding of one's own body and energy system through practices like yoga and meditation rather than solely relying on external concepts and information.
Sadhguru on Cancer - A Yogic PerspectiveAlina157681
Â
Health is important to everyone. Body, mind, emotion and emotion when tuned together you feel wholesome with yourself. This book is an amalgamation of excerpts taken from various discourses by Sadhguru on Cancer by a yogic perspective.
This document discusses concepts of health and disease from various perspectives. It defines health as a state of complete physical, mental, and social well-being according to the WHO. Health has physical, mental, and social dimensions. The determinants of health include heredity, environment, health services, and human behavior and lifestyle. Disease is defined as a physiological or psychological dysfunction and includes an individual's perceptions and responses. The natural history of a disease over time is also examined, from susceptibility to clinical symptoms to resolution or termination with potential sequels.
BSC NURSING I YEAR. Nursing foundations. unit 1 introductionMary Lalitha Kala C
Â
The document discusses various concepts related to health, wellness, illness, and the body's defenses against pathogens. It defines health according to the WHO as a state of complete physical, mental and social well-being, not just the absence of disease. Wellness refers to overall well-being and is determined by multiple dimensions including physical, social, emotional, intellectual, spiritual, occupational, and environmental factors. Illness is defined as a disease or period of sickness, and the sick role refers to the rights and obligations that come with being ill. The body protects itself through innate immunity mechanisms like skin and mucous barriers as well as acquired immunity developed after exposure to pathogens through vaccination or previous infections.
The document discusses concepts of health, wellness, illness, and factors that influence health. It defines health as a state of complete physical, mental, and social well-being, not just the absence of disease. Wellness refers to overall well-being and is plotted on a continuum from illness to optimal wellness. Illness is defined as a disease or period of sickness. Factors influencing health include biological, environmental, lifestyle, and psychological factors. The determinants of health encompass the social environment, physical environment, and individual behaviors and characteristics. Illness can impact patients and families by causing changes to roles and increasing stress and economic strain.
We believe the best way deliver a great user experience is by deeply understanding what people want and love. Then deliver the features, messages, and content that are most helpful, relevant and timely. That’s what makes users happy and loyal. Good nutrition is the key to good mental and physical health. Eating a balanced diet is an important part of good health for everyone. The kind and amount of food you eat affects the way you feel and how your body works.
Learn more visit us on www.nutrifitart.com
This document discusses concepts of health, disease, and their determinants. It defines health as a state of complete physical, mental, and social well-being according to the WHO. Physical health means normal body structure and functions, while mental health is a state of well-being and ability to cope with stress. Social well-being refers to ability to interact with others. Key determinants of health include heredity, environment, health services, and behaviors. Disease is defined as a physiological or psychological dysfunction, and natural history of disease describes its typical progression over time.
This document discusses concepts of health, disease, and their determinants. It defines health as a state of complete physical, mental, and social well-being according to the WHO. Physical health means normal body structure and functions, while mental health is a state of well-being and ability to cope with stress. Social well-being refers to ability to interact with others. Key determinants of health include heredity, environment, health services, and behaviors. Disease is defined as a physiological or psychological dysfunction, and natural history of disease describes its typical progression over time.
This document discusses concepts of health, disease, and their determinants. It defines health as a state of complete physical, mental, and social well-being according to the WHO. Physical health means normal body structure and functions, while mental health is a state of well-being and ability to cope with stress. Social well-being refers to ability to interact with others. Key determinants of health include heredity, environment, health services, and behaviors. Disease is defined as a physiological or psychological dysfunction, and natural history of disease describes its typical progression over time.
This document discusses concepts of health, disease, and their determinants. It defines health as a state of complete physical, mental, and social well-being according to the WHO. Physical health means normal body structure and functions, while mental health is a state of well-being and ability to cope with stress. Social well-being refers to ability to interact with others. Key determinants of health include heredity, environment, health services, and behaviors. Disease is defined as a physiological or psychological dysfunction, and natural history of disease describes its typical progression over time.
This document discusses concepts of health, disease, and their determinants. It defines health as a state of complete physical, mental, and social well-being according to the WHO. Physical health means normal body structure and functions, while mental health is a state of well-being and ability to cope with stress. Social well-being refers to ability to interact with others. Key determinants of health include heredity, environment, health services, and behaviors. Disease is defined as a physiological or psychological dysfunction, and natural history of disease describes its typical progression over time.
19 con health.pdf good quality content help studentskush23316
Â
This document provides an overview of concepts related to health, including definitions of health, the spectrum of health, dimensions and determinants of health, and the natural history of disease. It discusses health from anatomical, physiological, biochemical, and other perspectives. Key points include: health is defined by the WHO as a state of complete physical, mental and social well-being; dimensions of health include physical, mental, and social wellbeing; determinants include heredity, environment, health services, behavior; and disease progresses through stages of susceptibility, pre-symptomatic disease, clinical disease, termination, and potential sequels.
The document discusses the importance of living a healthy lifestyle. It defines health as a state of complete physical, mental, and social well-being. Maintaining a clean bloodstream is essential for good health as the blood transports substances throughout the body and infections often enter through blood. Proper diet, exercise, and avoiding harmful substances like cigarettes are emphasized. A positive mental attitude can also impact health; focusing on happiness and suppressing pain can help conditions. Living healthily requires consistent self-awareness of one's behaviors and discipline in making good choices.
This document discusses the concept of health from various perspectives. It begins by explaining how health has traditionally been viewed through a biomedical lens as the absence of disease. However, more modern concepts recognize health as influenced by ecological, psychosocial, and holistic factors as well. The World Health Organization defines health as complete physical, mental, social, and spiritual well-being, not just the absence of disease. The document further explores the dimensions of health, including physical, mental, social, and spiritual health. It provides examples of what constitutes good health in each of these dimensions.
The document discusses different perspectives on defining health. It contrasts a narrow view of health as merely the absence of disease with the WHO's broader definition of health as complete physical, mental, and social well-being. It identifies key components of health, including physical, mental/psychological, and social well-being. Maintaining relationships and fulfilling social roles are seen as important for social health. Approaches to improving health include legal, service provision, and educational interventions.
Essay about Health and Wellbeing
Essay on Definitions of Health
Essay about A Healthy Heart
Essay about Philosophy of Health
Maintaining a Healthy Body Essay example
Nutrition and Health Essay
Health Care Persuasive Essay
Good Health.
Health Goal Essay
Essay about Health and Wellbeing
Health and Exercise Essay
A sequence of 12 slides shows us a new evidence of a healthy life we all are really born to. Then what is a role of the complementary medicine at the background of human\’s body regular biology. It counterpart the role of a health problem and where is the right place of conventional and the complementary medicine.
This document provides a summary of a November 2009 newsletter from TriVita.com that includes the following:
1) An offer for a free product, FREE ENERGY NOW!, with the purchase of two other products, Nopalea and Sublingual B-12.
2) Stories about how Nopalea helped ease aches and pains from injuries in a rodeo rider and how it and Sublingual B-12 work as an anti-inflammatory duo.
3) A message from the CEO of TriVita about pursuing health reform that encourages supplementation and healthy lifestyle choices rather than just focusing on political debates over healthcare.
1. The student was asked to grow an uncontaminated culture of microbes. The method provided involved sterilizing equipment, heating an inoculating loop, spreading bacteria onto agar jelly in a petri dish, and incubating the dish at 25°C.
2. The student tested the effectiveness of four antibiotic solutions by placing sterile paper discs dipped in each solution onto agar with growing bacteria. After two days of incubation, different sized regions with no bacterial growth were observed around each disc.
3. The least effective antibiotic produced the smallest region without bacteria, as the size of this region indicates how strongly the antibiotic inhibited bacterial growth. Calculations of the area of the bacterial-free zones would be inaccurate
Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium that causes difficult-to-treat infections in humans. MRSA developed from a similar strain called Methicillin-sensitive Staphylococcus aureus (MSSA) that was treatable with antibiotics. Through natural selection, some MSSA bacteria gained mutations that made them resistant to antibiotics. Those resistant bacteria survived exposure to antibiotics and passed on the resistance genes through asexual reproduction, leading to the emergence of the MRSA strain.
The document discusses antibiotic resistance, specifically Methicillin-resistant Staphylococcus aureus (MRSA). MRSA infections are difficult to treat with antibiotics that previously worked. This is because MRSA developed from a strain called Methicillin-sensitive Staphylococcus aureus that was susceptible to antibiotics, through natural selection whereby bacteria resistant to antibiotics survived and passed on those resistance genes. New treatments are needed to kill MRSA since existing antibiotics are no longer effective.
The document summarizes data from a hospital in the 1800s that showed higher death rates for women giving birth in Ward A compared to Ward B. After 1840, only doctors worked in Ward A while only midwives worked in Ward B, resulting in a much lower death rate in Ward B. In 1847, Semmelweis required doctors to wash their hands with chloride of lime before childbirth. This led to a significant reduction in the Ward A death rate in 1848-1849, bringing it closer to the rate in Ward B. The hand washing killed bacteria that doctors were transmitting from autopsies to women during childbirth.
The document summarizes data from the 1800s that showed death rates of women giving birth in two hospital wards: Ward A and Ward B. Before 1840, both wards had similar high death rates as doctors and midwives worked in both. After 1840, Ward A had only doctors while Ward B had only midwives, and Ward B saw significantly lower death rates. Dr. Semmelweis later required doctors to wash their hands in chloride of lime solution before deliveries in Ward A, which further reduced Ward A's death rate to match Ward B's lower level.
Tuberculosis (TB) is caused by the Mycobacterium tuberculosis bacterium. When someone with TB coughs or sneezes, the bacteria are expelled into the air and can be inhaled by others. If breathed in, the bacteria initially infect the lungs. In the lungs, the bacteria can multiply and cause lesions and inflammation. Other types of microorganisms besides bacteria, such as viruses, can also cause infectious disease. When the body is exposed to TB bacteria, it mounts an immune response to fight the infection by using white blood cells, antibodies, and other mechanisms of defense.
The document discusses diet, exercise, and metabolic rate. It defines metabolic rate as the rate of chemical reactions in the body. While genes affect metabolic rate, exercise can increase it. A balanced diet with carbohydrates, proteins, and fats provides energy, builds cells, and stores energy. An imbalanced diet can lead to malnutrition by providing too much or too little energy compared to what the body needs. The document questions an advert claiming quick weight loss from a program, as it lacks long-term data and sample size details.
The document discusses diet, exercise, and weight management. It defines metabolic rate as the rate at which the body burns calories and explains that some people have naturally low metabolic rates. It recommends exercise as a way to increase metabolic rate. Diet components like carbohydrates, proteins, and fats serve important functions, and an imbalanced diet can lead to malnutrition. The document questions the validity of an advert claiming quick weight loss from a "Dropweight" program based on reported one-day results.
Tuberculosis (TB) is caused by the Mycobacterium tuberculosis bacterium. When people with TB cough or sneeze, they expel the bacteria into the air. If others breathe these bacteria in, they can become infected. The bacteria first infect the lungs or bronchioles. In the body, the bacteria produce toxins that damage cells. The body fights the infection through white blood cells that engulf and destroy bacteria and produce antibodies and antitoxins. Vaccines work by exposing the body to an inactive form of the disease-causing microbe, allowing it to develop antibodies without risk of illness. These antibodies then provide future protection against the live microbe.
1) The document is a revision checklist for additional GCSE science covering topics in physics including forces, motion, braking, terminal velocity, elasticity, energy, momentum, static electricity, electrical circuits, household electricity, current, charge, power, atomic structure, radiation, nuclear fission, and nuclear fusion.
2) It lists key terms, concepts, and formulas to define and explanations to provide for each topic.
3) The checklist provides resources for students to review physics content and ensure they understand the essential information for their GCSE exam.
This document contains a revision checklist for the GCSE Core Science P1 Physics exam. It lists several topics and subtopics that students should review in preparation for the exam, including: infrared radiation; states of matter; conduction, convection, and evaporation/condensation as methods of heat transfer; factors affecting the rate of heat transfer; solar panels; specific heat capacity; energy efficiency and Sankey diagrams; electrical appliances and calculating energy transfers; methods of generating electricity including alternative sources; the National Grid; waves including transverse/longitudinal waves, electromagnetic spectrum, reflection, refraction, and diffraction of waves; and Doppler effect and evidence for the Big Bang theory.
This document provides an overview of the content covered in additional science C2: chemistry. It outlines several key topics in chemistry including structure and bonding, atomic structure and quantitative chemistry, rates of reaction, endo/exothermic reactions, acids bases and salts, and electrolysis. For each topic, it lists the main concepts, definitions, and processes that students are expected to understand at a higher level, such as describing bonding using diagrams, calculating relative formula mass, explaining how factors affect reaction rates, writing equations for acid-base reactions, and describing electrolysis processes and products. The document serves as a revision checklist for students to ensure they have learned the essential high-level information and skills for the additional chemistry content.
This document is a revision checklist for GCSE core science covering various topics in chemistry. It provides a list of key concepts and processes to review for each topic, including fundamental chemistry ideas like atomic structure, limestone and building materials, metals and their uses, crude oil and fuels, and changes to the Earth's atmosphere. For each item, it indicates related videos, exam questions, and whether it is core or higher content.
This document provides an outline of topics covered in Additional Science B2: Biology. It includes sections on cells and transport, tissues and organ systems, photosynthesis, organisms and their environment, aerobic and anaerobic respiration, cell division and inheritance, speciation, and includes learning objectives for each section such as describing processes like diffusion, the roles of organs in the digestive system, the process of photosynthesis, and more. It also provides exam questions, activities, and checkpoints to evaluate understanding of the material.
This document provides an overview of topics covered in a biology course, including:
- The components of a balanced diet and how exercise affects health.
- How pathogens make us ill and how the body protects against them.
- The development and testing of medical drugs, and issues around drug dependence.
- Genetic variation, inheritance, and different types of reproduction.
- Evolution by natural selection and genetic variation over generations.
- Ecological concepts like food chains, nutrient cycling, and indicator species.
X-rays have a short wavelength and can cause ionization. They are used in medicine for diagnosis and treatment, but precautions must be taken when operating X-ray machines. Ultrasound uses high frequency sound waves above the human hearing range. The waves reflect off boundaries and the time of reflections can be used to determine distances between interfaces in different media. Lenses refract light to form images. A convex lens brings parallel rays to a focus at its principal focus, defined by the focal length. The nature of images depends on size, orientation, and whether real or virtual.
The document summarizes key concepts in chemistry including the periodic table, properties of groups in the periodic table, hard and soft water, chemical reactions, and organic compounds. It describes how elements are arranged in the modern periodic table by electronic structure and properties of groups such as metals, nonmetals, and halogens. It also discusses chemical tests and reactions including flame tests, precipitation reactions, acid-base titrations, and the production of ammonia via the Haber process.
This document provides information on various biology topics including:
- Diffusion and osmosis, the movement of substances through membranes. Active transport requires energy.
- Exchange surfaces are effective with large surface area, thinness, good blood supply and ventilation like in alveoli and villi.
- During breathing, the ribcage and diaphragm work to decrease thoracic pressure and draw air into the lungs. Artificial aids can help breathing.
- In plants, carbon dioxide enters leaves and water and minerals are absorbed by roots, transported by xylem and phloem.
- The heart has four chambers and pumps blood through two circulation systems. Blood flows through arteries, veins
The document discusses key economic concepts related to government objectives and the functioning of the economy. It covers topics such as different types of economies, market failures including externalities and public goods, the economic cycle, fiscal and monetary policies, and the role of the EU. The key points are that candidates should understand the principal objectives of governments in terms of economic growth, employment, prices and trade balances. They should also be aware of how markets can fail to allocate resources efficiently and the roles of government and central banks in addressing these issues.
The document outlines a specification for teaching personal finance concepts. It covers understanding the personal lifecycle and how needs and wants change throughout different stages of life. Students will learn to make financial decisions by weighing costs and benefits and considering opportunity costs. They will also explore concepts related to spending, saving, borrowing money, and managing personal finances. The specification also addresses topics related to work, including rewards, labor markets, unemployment, and the impact of globalization. Finally, it covers understanding international trade, exchange rates, and the influence of consumers on national and global economies.
1. C hapter 13
WHY DO WE FALL ILL
Activity _____________ 13.1 the kidney is filtering urine, the brain is
thinking.
• We have all heard of the earthquakes All these activities are interconnected. For
in Latur, Bhuj, Kashmir etc. or the example, if the kidneys are not filtering urine,
cyclones that attack the coastal poisonous substances will accumulate. Under
regions. Think of as many different such conditions, the brain will not be able to
ways as possible in which people’s
think properly. For all these interconnected
health would be affected by such a
disaster if it took place in our
activities, energy and raw material are needed
neighbourhood. from outside the body. In other words, food
• How many of these ways we can think of is a necessity for cell and tissue functions.
are events that would occur when the Anything that prevents proper functioning of
disaster is actually happening? cells and tissues will lead to a lack of proper
• How many of these health-related events activity of the body.
would happen long after the actual It is in this context that we will now look
disaster, but would still be because of the at the notions of health and disease.
disaster?
• Why would one effect on health fall into
the first group, and why would another 13.1 Health and its Failure
fall into the second group?
13.1.1 THE SIGNIFICANCE OF ‘HEALTH’
When we do this exercise, we realise that
health and disease in human communities We have heard the word ‘health’ used quite
are very complex issues, with many frequently all around us. We use it ourselves
interconnected causes. We also realise that as well, when we say things like ‘my
the ideas of what ‘health’ and ‘disease’ mean grandmother’s health is not good’. Our
are themselves very complicated. When we teachers use it when they scold us saying ‘this
ask what causes diseases and how we prevent is not a healthy attitude’. What does the word
them, we have to begin by asking what these ‘health’ mean?
notions mean. If we think about it, we realise that it
We have seen that cells are the basic units always implies the idea of ‘being well’. We can
of living beings. Cells are made of a variety of think of this well-being as ef fective
chemical substances – proteins, carbo- functioning. For our grandmothers, being able
hydrates, fats or lipids, and so on. Although to go out to the market or to visit neighbours
the pictures look quite static, in reality the is ‘being well’, and not being able to do such
living cell is a dynamic place. Something or things is ‘poor health’. Being interested in
the other is always happening. Cells move following the teaching in the classroom so that
from place to place. Even in cells that do not we can understand the world is called a
move, there is repair going on. New cells are ‘healthy attitude’; while not being interested
being made. In our organs or tissues, there is called the opposite. ‘Health’ is therefore a
are various specialised activities going on – state of being well enough to function well
the heart is beating, the lungs are breathing, physically, mentally and socially.
2. 13.1.2 PERSONAL AND COMMUNITY ISSUES We need food for health, and this food will
have to be earned by doing work. For this,
BOTH MATTER FOR HEALTH
the opportunity to do work has to be available.
If health means a state of physical, mental Good economic conditions and jobs are
and social well-being, it cannot be something therefore needed for individual health.
that each one of us can achieve entirely on We need to be happy in order to be truly
our own. The health of all organisms will healthy, and if we mistreat each other and
depend on their surroundings or their are afraid of each other, we cannot be happy
environment. The environment includes the or healthy. Social equality and harmony are
physical environment. So, for example, health therefore necessary for individual health. We
is at risk in a cyclone in many ways. can think of many other such examples of
But even more importantly, human beings connections between community issues and
live in societies. Our social environment, individual health.
therefore, is an important factor in our
individual health. We live in villages, towns 13.1.3 DISTINCTIONS BETWEEN ‘HEALTHY’
or cities. In such places, even our physical AND ‘DISEASE-FREE’
environment is decided by our social
environment. If this is what we mean by ‘health’, what do
Consider what would happen if no agency we mean by ‘disease’? The word is actually
is ensuring that garbage is collected and self-explanatory – we can think of it as
disposed. What would happen if no one takes ‘disease’ – disturbed ease. Disease, in other
responsibility for clearing the drains and words, literally means being uncomfortable.
ensuring that water does not collect in the However, the word is used in a more limited
streets or open spaces? meaning. We talk of disease when we can find
So, if there is a great deal of garbage a specific and particular cause for discomfort.
thrown in our streets, or if there is open drain- This does not mean that we have to know the
water lying stagnant around where we live, absolute final cause; we can say that
the possibility of poor health increases. someone is suffering from diarrhoea without
Therefore, public cleanliness is important for knowing exactly what has caused the loose
individual health. motions.
We can now easily see that it is possible
Activity _____________ 13.2 to be in poor health without actually suffering
from a particular disease. Simply not being
• Find out what provisions are made by diseased is not the same as being healthy.
your local authority (panchayat/ ‘Good health’ for a dancer may mean being
municipal corporation) for the supply
able to stretch his body into difficult but
of clean drinking water.
• Are all the people in your locality able
graceful positions. On the other hand, good
to access this? health for a musician may mean having enough
breathing capacity in his/her lungs to control
Activity _____________ 13.3 the notes from his/her flute. To have the
opportunity to realise the unique potential
• Find out how your local authority in all of us is also necessary for real health.
manages the solid waste generated in So, we can be in poor health without there
your neighbourhood.
being a simple cause in the form of an
• Are these measures adequate?
identifiable disease. This is the reason why,
• If not, what improvements would you
suggest? when we think about health, we think about
• What could your family do to reduce societies and communities. On the other
the amount of solid waste generated hand, when we think about disease, we think
during a day/week? about individual sufferers.
WHY DO WE FALL ILL 177
3. Q
uestions 13.2.2 ACUTE AND CHRONIC DISEASES
1. State any two conditions The manifestations of disease will be different
essential for good health. depending on a number of factors. One of the
2. State any two conditions most obvious factors that determine how we
essential for being free of disease. perceive the disease is its duration. Some
3. Are the answers to the above diseases last for only very short periods of
questions necessarily the same time, and these are called acute diseases. We
or different? Why? all know from experience that the common
cold lasts only a few days. Other ailments can
13.2 Disease and Its Causes last for a long time, even as much as a lifetime,
and are called chronic diseases. An example
13.2.1 WHAT DOES DISEASE LOOK LIKE? is the infection causing elephantiasis, which
is very common in some parts of India.
Let us now think a little more about diseases.
In the first place, how do we know that there Activity _____________ 13.4
is a disease? In other words, how do we know
• Survey your neighbourhood to find out:
that there is something wrong with the body?
(1) how many people suffered from
There are many tissues in the body, as we acute diseases during the last three
have seen in Chapter 6. These tissues make months,
up physiological systems or organ systems (2) how many people developed chronic
that carry out body functions. Each of the diseases during this same period,
organ systems has specific organs as its parts, (3) and finally, the total number of
and it has particular functions. So, the people suf fering from chronic
digestive system has the stomach and diseases in your neighbourhood.
intestines, and it helps to digest food taken • Are the answers to questions (1) and
(2) different?
in from outside the body. The musculoskeletal
• Are the answers to questions (2) and
system, which is made up of bones and (3) different?
muscles, holds the body parts together and • What do you think could be the reason
helps the body move. for these differences? What do you think
When there is a disease, either the would be the effect of these differences
functioning or the appearance of one or more on the general health of the population?
systems of the body will change for the worse.
These changes give rise to symptoms and 13.2.3 C HRONIC DISEASES AND POOR
signs of disease. Symptoms of disease are the HEALTH
things we feel as being ‘wrong’. So we have a
headache, we have cough, we have loose As we can imagine, acute and chronic
motions, we have a wound with pus; these diseases have different effects on our health.
are all symptoms. These indicate that there Any disease that causes poor functioning of
may be a disease, but they don’t indicate what some part of the body will affect our general
the disease is. For example, a headache may health as well. This is because all functions
mean just examination stress or, very rarely, of the body are necessary for general health.
it may mean meningitis, or any one of a dozen But an acute disease, which is over very soon,
different diseases. will not have time to cause major effects on
Signs of disease are what physicians will general health, while a chronic disease will
look for on the basis of the symptoms. Signs do so.
will give a little more definite indication of As an example, think about a cough and
the presence of a particular disease. cold, which all of us have from time to time.
Physicians will also get laboratory tests done Most of us get better and become well within
to pinpoint the disease further. a week or so. And there are no bad effects on
178 SCIENCE
4. our health. We do not lose weight, we do not would not lead to loose motions. But they do
become short of breath, we do not feel tired become contributory causes of the disease.
all the time because of a few days of cough Why was there no clean drinking water
and cold. But if we get infected with a chronic for the baby? Perhaps because the public
disease such as tuberculosis of the lungs, services are poor where the baby’s family
then being ill over the years does make us lives. So, poverty or lack of public services
lose weight and feel tired all the time. become third-level causes of the baby’s
We may not go to school for a few days if disease.
we have an acute disease. But a chronic It will now be obvious that all diseases
disease will make it difficult for us to follow will have immediate causes and contributory
what is being taught in school and reduce causes. Also, most diseases will have many
our ability to learn. In other words, we are causes, rather than one single cause.
likely to have prolonged general poor health
if we have a chronic disease. Chronic diseases 13.2.5 INFECTIOUS AND NON-INFECTIOUS
therefore, have very drastic long-term effects CAUSES
on people’s health as compared to acute
diseases. As we have seen, it is important to keep public
health and community health factors in mind
13.2.4 CAUSES OF DISEASES when we think about causes of diseases. We
can take that approach a little further. It is
What causes disease? When we think about useful to think of the immediate causes of
causes of diseases, we must remember that disease as belonging to two distinct types. One
there are many levels of such causes. Let us group of causes is the infectious agents,
look at an example. If there is a baby suffering mostly microbes or micro-organisms.
from loose motions, we can say that the cause Diseases where microbes are the immediate
of the loose motions is an infection with a causes are called infectious diseases. This is
virus. So the immediate cause of the disease because the microbes can spread in the
is a virus. community, and the diseases they cause will
But the next question is – where did the spread with them.
virus come from? Suppose we find that the
virus came through unclean drinking water. Things to ponder
But many babies must have had this unclean 1. Do all diseases spread to people
drinking water. So, why is it that one baby coming in contact with a sick person?
developed loose motions when the other 2. What are the diseases that are not
babies did not? spreading?
One reason might be that this baby is not 3. How would a person develop those
healthy. As a result, it might be more likely diseases that don’t spread by contact
to have disease when exposed to risk, whereas with a sick person?
healthier babies would not. Why is the baby
not healthy? Perhaps because it is not well On the other hand, there are also diseases
nourished and does not get enough food. So, that are not caused by infectious agents. Their
lack of good nourishment becomes a second- causes vary, but they are not external causes
level cause of the disease the baby is suffering like microbes that can spread in the
from. Further, why is the baby not well community. Instead, these are mostly
nourished? Perhaps because it is from a internal, non-infectious causes.
household which is poor. For example, some cancers are caused by
It is also possible that the baby has some genetic abnormalities. High blood pressure
genetic difference that makes it more likely can be caused by excessive weight and lack
to suffer from loose motions when exposed of exercise. You can think of many other
to such a virus. Without the virus, the genetic diseases where the immediate causes will not
difference or the poor nourishment alone be infectious.
WHY DO WE FALL ILL 179
5. The ways in which diseases spread, and
Peptic ulcers and the Nobel prize the ways in which they can be treated and
For many years, everybody used to think prevented at the community level would be
that peptic ulcers, which cause acidity– different for different diseases. This would
related pain and bleeding in the stomach depend a lot on whether the immediate
and duodenum, were because of lifestyle causes are infectious or non-infectious.
reasons. Everybody thought that a
Q
stressful life led to a lot of acid secretion
in the stomach, and eventually caused
peptic ulcers. uestions
Then two Australians made a discovery
1. List any three reasons why you
that a bacterium, Helicobacter pylori, was
responsible for peptic ulcers. Robin Warren would think that you are sick and
(born 1937), a pathologist from Perth, ought to see a doctor. If only one
Australia, saw these small curved bacteria of these symptoms were present,
in the lower part of the stomach in many would you still go to the doctor?
patients. He noticed that signs of Why or why not?
inflammation were always present around 2. In which of the following case do
these bacteria. Barry Marshall (born 1951),
you think the long-term effects on
a young clinical fellow, became interested
your health are likely to be most
in Warren’s findings and succeeded in
cultivating the bacteria from these sources. unpleasant?
In treatment studies, Marshall and • if you get jaundice,
Warren showed that patients could be • if you get lice,
cured of peptic ulcer only when the • if you get acne.
bacteria were killed off from the stomach. Why?
Thanks to this pioneering discovery by
Marshall and Warren, peptic ulcer disease
is no longer a chronic, frequently disabling 13.3 Infectious Diseases
condition, but a disease that can be cured
by a short period of treatment with
antibiotics. 13.3.1 INFECTIOUS AGENTS
We have seen that the entire diversity seen in
the living world can be classified into a few
groups. This classification is based on
common characteristics between different
organisms. Organisms that can cause disease
are found in a wide range of such categories
of classification. Some of them are viruses,
some are bacteria, some are fungi, some are
single-celled animals or protozoans. Some
For this achievement, Marshall and diseases are also caused by multicellular
Warren (seen in the picture) received the organisms, such as worms of different kinds.
Nobel prize for physiology and medicine
in 2005.
180 SCIENCE
6. Fig. 13.1(a): Picture of SARS viruses coming out (see
arrows for examples) of the surface of
an infected cell. The white scale line
represents 500 nanometres, which is
half a micrometre, which is one-
thousandth of a millimetre. The scale line
gives us an idea of how small the things
we are looking at are.
Fig. 13.1(d): Picture of Leishmania, the protozoan
Courtesy: Emerging Infectious
organism that causes kala-azar. The
Deseases, a journal of CDC, U.S.
organisms are oval-shaped, and each
has one long whip-like structure. One
organism (arrow) is dividing, while a cell
of the immune system (lower right) has
gripped on the two whips of the dividing
organism and is sending cell processes
up to eat up the organism. The immune
cell is about ten micrometres in diameter.
Fig. 13.1(b): Picture of staphylococci, the bacteria
which can cause acne. The scale of the
image is indicated by the line at top left,
which is 5 micrometres long.
Fig. 13.1(c): Picture of Trypanosoma, the protozoan
organism responsible for sleeping
sickness. The organism is lying next to Fig. 13.1(e): Picture of an adult roundworm (Ascaris
a saucer-shaped red blood cell to give lumbricoides is the technical name) from
an idea of the scale. the small intestine. The ruler next to it
Copyright: Oregon Health and Science shows four centimetres to give us an
University, U.S. idea of the scale.
WHY DO WE FALL ILL 181
7. Common examples of diseases caused by But viruses do not use these pathways at
viruses are the common cold, influenza, all, and that is the reason why antibiotics do
dengue fever and AIDS. Diseases like typhoid not work against viral infections. If we have a
fever, cholera, tuberculosis and anthrax are common cold, taking antibiotics does not
caused by bacteria. Many common skin reduce the severity or the duration of the
infections are caused by different kinds of disease. However, if we also get a bacterial
fungi. Protozoan microbes cause many infection along with the viral cold, taking
familiar diseases, such as malaria and kala- antibiotics will help. Even then, the antibiotic
azar. All of us have also come across intestinal will work only against the bacterial part of
worm infections, as well as diseases like the infection, not the viral infection.
elephantiasis caused by diffferent species of
worms. Activity _____________ 13.5
Why is it important that we think of these
categories of infectious agents? The answer • Find out how many of you in your class
is that these categories are important factors had cold/cough/fever recently.
in deciding what kind of treatment to use. • How long did the illness last?
• How many of you took antibiotics (ask
Members of each one of these groups –
your parents if you had antibiotics)?
viruses, bacteria, and so on – have many
• How long wer e those who took
biological characteristics in common.
antibiotics ill?
All viruses, for example, live inside host • How long were those who didn’t take
cells, whereas bacteria very rarely do. Viruses, antibiotics ill?
bacteria and fungi multiply very quickly, while • Is there a difference between these two
worms multiply very slowly in comparison. groups?
Taxonomically, all bacteria are closely related • If yes, why? If not, why not?
to each other than to viruses and vice versa.
This means that many important life
processes are similar in the bacteria group
13.3.2 MEANS OF SPREAD
but are not shared with the virus group. As a How do infectious diseases spread? Many
result, drugs that block one of these life microbial agents can commonly move from
processes in one member of the group is likely an affected person to someone else in a variety
to be effective against many other members of ways. In other words, they can be
of the group. But the same drug will not work ‘communicated’, and so are also called
against a microbe belonging to a different communicable diseases.
group. Such disease-causing microbes can
As an example, let us take antibiotics. spread through the air. This occurs through
They commonly block biochemical pathways the little droplets thrown out by an infected
important for bacteria. Many bacteria, for
person who sneezes or coughs. Someone
example, make a cell-wall to protect
standing close by can breathe in these
themselves. The antibiotic penicillin blocks
droplets, and the microbes get a chance to
the bacterial processes that build the cell-
wall. As a result, the growing bacteria become start a new infection. Examples of such
unable to make cell-walls, and die easily. diseases spread through the air are the
Human cells don’t make a cell-wall anyway, common cold, pneumonia and tuberculosis.
so penicillin cannot have such an effect on We all have had the experience of sitting
us. Penicillin will have this effect on any near someone suffering from a cold and
bacteria that use such processes for making catching it ourselves. Obviously, the more
cell-walls. Similarly, many antibiotics work crowded our living conditions are, the more
against many species of bacteria rather than likely it is that such airborne diseases will
simply working against one. spread.
182 SCIENCE
8. inevitable that many diseases will be
transmitted by other animals. These animals
carry the infecting agents from a sick person
to another potential host. These animals are
thus the intermediaries and are called
vectors. The commonest vectors we all know
are mosquitoes. In many species of
mosquitoes, the females need highly
nutritious food in the form of blood in order
to be able to lay mature eggs. Mosquitoes feed
on many warm-blooded animals, including
us. In this way, they can transfer diseases
from person to person.
Fig. 13.2: Air-transmitted diseases are easier to
catch the closer we are to the infected
person. However, in closed areas, the
droplet nuclei recirculate and pose a risk
to everybody. Overcrowded and poorly
ventilated housing is therefore a major
factor in the spread of airborne diseases.
Diseases can also be spread through
water. This occurs if the excreta from someone
suffering from an infectious gut disease, such
as cholera, get mixed with the drinking water
used by people living nearby. The cholera-
causing microbes will enter new hosts
through the water they drink and cause
disease in them. Such diseases are much
more likely to spread in the absence of safe
supplies of drinking water. Fig. 13.3: Common methods of transmission of
The sexual act is one of the closest diseases.
physical contact two people can have with
each other. Not surprisingly, there are
microbial diseases such as syphilis or AIDS 13.3.3 O RGAN - SPECIFIC AND TISSUE -
that are transmitted by sexual contact from SPECIFIC MANIFESTATIONS
one partner to the other. However, such
sexually transmitted diseases are not spread The disease-causing microbes enter the body
by casual physical contact. Casual physical through these different means. Where do they
contacts include handshakes or hugs or go then? The body is very large when
sports, like wrestling, or by any of the other compared to the microbes. So there are many
ways in which we touch each other socially. possible places, organs or tissues, where they
Other than the sexual contact, the AIDS virus could go. Do all microbes go to the same tissue
can also spread through blood-to-blood or organ, or do they go to different ones?
contact with infected people or from an Different species of microbes seem to have
infected mother to her baby during pregnancy evolved to home in on different parts of the
or through breast feeding. body. In part, this selection is connected to
We live in an environment that is full of their point of entry. If they enter from the air
many other creatures apart from us. It is via the nose, they are likely to go to the lungs.
WHY DO WE FALL ILL 183
9. This is seen in the bacteria causing minor gut infection can produce major
tuberculosis. If they enter through the mouth, diarrhoea with blood loss. Ultimately, it is
they can stay in the gut lining like typhoid- these other infections that kill people
causing bacteria. Or they can go to the liver, suffering from HIV-AIDS.
like the viruses that cause jaundice. It is also important to remember that the
But this needn’t always be the case. An severity of disease manifestations depend on
infection like HIV, that comes into the body the number of microbes in the body. If the
via the sexual organs, will spread to lymph number of microbes is very small, the disease
nodes all over the body. Malaria-causing manifestations may be minor or unnoticed.
microbes, entering through a mosquito bite, But if the number is of the same microbe
will go to the liver, and then to the red blood large, the disease can be severe enough to be
cells. The virus causing Japanese life-threatening. The immune system is a
encephalitis, or brain fever, will similarly enter major factor that determines the number of
through a mosquito bite. But it goes on to microbes surviving in the body. We shall look
infect the brain. into this aspect a little later in the chapter.
The signs and symptoms of a disease will
thus depend on the tissue or organ which 13.3.4 PRINCIPLES OF TREATMENT
the microbe targets. If the lungs are the
targets, then symptoms will be cough and What are the steps taken by your family when
breathlessness. If the liver is targeted, there you fall sick? Have you ever thought why you
sometimes feel better if you sleep for some
will be jaundice. If the brain is the target, we
time? When does the treatment involve
will observe headaches, vomiting, fits or
medicines?
unconsciousness. We can imagine what the
Based on what we have learnt so far, it
symptoms and signs of an infection will be if
would appear that there are two ways to treat
we know what the target tissue or organ is,
an infectious disease. One would be to reduce
and the functions that are carried out by this
the effects of the disease and the other to kill
tissue or organ.
the cause of the disease. For the first, we can
In addition to these tissue-specific effects
of infectious disease, there will be other provide treatment that will reduce the
common effects too. Most of these common symptoms. The symptoms are usually
effects depend on the fact that the body’s because of inflammation. For example, we can
immune system is activated in response to take medicines that bring down fever, reduce
infection. An active immune system recruits pain or loose motions. We can take bed rest so
many cells to the affected tissue to kill off the that we can conserve our energy. This will
disease-causing microbes. This recruitment enable us to have more of it available to focus
process is called inflammation. As a part of on healing.
this process, there are local effects such as But this kind of symptom-directed
swelling and pain, and general effects such treatment by itself will not make the infecting
as fever. microbe go away and the disease will not be
In some cases, the tissue-specificity of the cured. For that, we need to be able to kill off
infection leads to very general-seeming the microbes.
effects. For example, in HIV infection, the How do we kill microbes? One way is to
virus goes to the immune system and use medicines that kill microbes. We have seen
damages its function. Thus, many of the earlier that microbes can be classified into
effects of HIV-AIDS are because the body can different categories. They are viruses, bacteria,
no longer fight off the many minor infections fungi or protozoa. Each of these groups of
that we face everyday. Instead, every small organisms will have some essential
cold can become pneumonia. Similarly, a biochemical life process which is peculiar to
184 SCIENCE
10. that group and not shared with the other we can get some easy answers. For airborne
groups. These processes may be pathways for microbes, we can prevent exposure by
the synthesis of new substances or respiration. providing living conditions that are not
These pathways will not be used by us overcrowded. For water-borne microbes, we
either. For example, our cells may make new can prevent exposure by providing safe
substances by a mechanism different from drinking water. This can be done by treating
that used by bacteria. We have to find a drug the water to kill any microbial contamination.
that blocks the bacterial synthesis pathway For vector-borne infections, we can provide
without affecting our own. This is what is clean environments. This would not, for
achieved by the antibiotics that we are all example, allow mosquito breeding. In other
familiar with. Similarly, there are drugs that words, public hygiene is one basic key to the
kill protozoa such as the malarial parasite. prevention of infectious diseases.
One reason why making anti-viral In addition to these issues that relate to
medicines is harder than making anti- the environment, there are some other general
bacterial medicines is that viruses have few principles to prevent infectious diseases. To
biochemical mechanisms of their own. They appreciate those principles, let us ask a
enter our cells and use our machinery for question we have not looked at so far.
their life processes. This means that there Normally, we are faced with infections
are relatively few virus-specific targets to aim everyday. If someone is suffering from a cold
at. Despite this limitation, there are now and cough in the class, it is likely that the
effective anti-viral drugs, for example, the children sitting around will be exposed to the
drugs that keep HIV infection under control. infection. But all of them do not actually suffer
from the disease. Why not?
13.3.5 PRINCIPLES OF PREVENTION This is because the immune system of our
body is normally fighting off microbes. We
All of what we have talked about so far deals have cells that specialise in killing infecting
with how to get rid of an infection in someone microbes. These cells go into action each time
who has the disease. But there are three infecting microbes enter the body. If they are
limitations of this approach to dealing with successful, we do not actually come down
infectious disease. The first is that once with any disease. The immune cells manage
someone has a disease, their body functions to kill off the infection long before it assumes
are damaged and may never recover
major proportions. As we noted earlier, if the
completely. The second is that treatment will
number of the infecting microbes is
take time, which means that someone
controlled, the manifestations of disease will
suffering from a disease is likely to be
be minor. In other words, becoming exposed
bedridden for some time even if we can give
to or infected with an infectious microbe does
proper treatment. The third is that the person
not necessarily mean developing noticeable
suffering from an infectious disease can serve
disease.
as the source from where the infection may
spread to other people. This leads to the So, one way of looking at severe infectious
multiplication of the above difficulties. It is diseases is that it represents a lack of success
because of such reasons that prevention of of the immune system. The functioning of the
diseases is better than their cure. immune system, like any other system in our
How can we prevent diseases? There are body, will not be good if proper and sufficient
two ways, one general and one specific to each nourishment and food is not available.
disease. The general ways of preventing Therefore, the second basic principle of
infections mostly relate to preventing prevention of infectious disease is the
exposure. How can we prevent exposure to availability of proper and sufficient food for
infectious microbes? everyone.
If we look at the means of their spreading,
WHY DO WE FALL ILL 185
11. Activity _____________ 13.6 immunisation.
• Conduct a survey in your locality. Immunisation
Talk to ten families who are well-off Traditional Indian and Chinese medicinal
and ten who are very poor (in your systems sometimes deliberately rubbed the
estimation). Both sets of families
skin crusts from smallpox victims into the
should have children who are below
skin of healthy people. They thus hoped
five years of age. Measure the heights
of these children. Draw a graph of the
to induce a mild form of smallpox that
height of each child against its age would create resistance against the
for both sets of families. disease.
• Is there a difference between the Famously, two centuries ago, an
groups? If yes, why? English physician
• If there is no difference, do you think named Edward
that your findings mean that being Jenner, realised
well-off or poor does not matter for that milkmaids
health? who had had
cowpox did not
These are the general ways of preventing
catch smallpox
infections. What are the specific ways? They
even during
relate to a peculiar property of the immune
epidemics.
system that usually fights off microbial
Cowpox is a very
infections. Let us cite an example to try and mild disease.
understand this property. Jenner tried
These days, there is no smallpox deliberately giving
anywhere in the world. But as recently as a cowpox to people
hundred years ago, smallpox epidemics were (as he can be seen doing in the picture), and
not at all uncommon. In such an epidemic, found that they were now resistant to
people used to be very afraid of coming near smallpox. This was because the smallpox
someone suffering from the disease since they virus is closely related to the cowpox virus.
were afraid of catching the disease. ‘Cow’ is ‘vacca’ in Latin, and cowpox is
However, there was one group of people ‘vaccinia’. From these roots, the word
who did not have this fear. These people would
provide nursing care for the victims of ‘vaccination’ has come into our usage.
smallpox. This was a group of people who had
had smallpox earlier and survived it, although We can now see that, as a general principle,
with a lot of scarring. In other words, if you we can ‘fool’ the immune system into
had smallpox once, there was no chance of developing a memory for a particular infection
suffering from it again. So, having the disease by putting something, that mimics the microbe
once was a means of preventing subsequent we want to vaccinate against, into the body.
attacks of the same disease. This does not actually cause the disease but
This happens because when the immune this would prevent any subsequent exposure
to the infecting microbe from turning into
system first sees an infectious microbe, it
actual disease.
responds against it and then remembers it
Many such vaccines are now available for
specifically. So the next time that particular preventing a whole range of infectious
microbe, or its close relatives enter the body, diseases, and provide a disease-specific
the immune system responds with even means of prevention. There are vaccines
greater vigour. This eliminates the infection against tetanus, diphtheria, whooping cough,
even more quickly than the first time around. measles, polio and many others. These form
This is the basis of the principle of the public health programme of childhood
186 SCIENCE
12. immunisation for preventing infectious humans and animals. Find out the
diseases. plan of your local authority for
Of course, such a programme can be the control of rabies in your
Q
useful only if such health measures are neighbourhood. Are these measures
available to all children. Can you think of adequate? If not, what improvements
would you suggest?
reasons why this should be so?
Some hepatitis viruses, which cause
jaundice, are transmitted through water. uestions
There is a vaccine for one of them, hepatitis 1. Why are we normally advised to
A, in the market. But the majority of children take bland and nourishing food
in many parts of India are already immune when we are sick?
to hepatitis A by the time they are five years 2. What are the different means by
old. This is because they are exposed to the which infectious diseases are
virus through water. Under these spread?
circumstances, would you take the vaccine? 3. What precautions can you take
in your school to reduce the
Activity _____________ 13.7 incidence of infectious diseases?
4. What is immunisation?
• Rabies virus is spread by the bite of
infected dogs and other animals. There 5. What are the immunisation
are anti-rabies vaccines for both programmes available at the
nearest health centre in your
locality? Which of these diseases are the major health problems in your area?
What
you have
learnt
• Health is a state of physical, mental and social well-being.
• The health of an individual is dependent on his/her physical
surroundings and his/her economic status.
• Diseases are classified as acute or chronic, depending on their
duration.
• Disease may be due to infectious or non-infectious causes.
• Infectious agents belong to different categories of organisms
and may be unicellular and microscopic or multicellular.
• The category to which a disease-causing organism belongs
decides the type of treatment.
• Infectious agents are spread through air, water, physical contact
or vectors.
• Prevention of disease is more desirable than its successful
treatment.
• Infectious diseases can be prevented by public health hygiene
WHY DO WE FALL ILL 187
13. measures that reduce exposure to infectious agents.
• Infectious diseases can also be prevented by using
immunisation.
• Effective prevention of infectious diseases in the community
requires that everyone should have access to public hygiene
and immunisation.
Exercises
1. How many times did you fall ill in the last one year? What were
the illnesses?
(a) Think of one change you could make in your habits in order
to avoid any of/most of the above illnesses.
(b) Think of one change you would wish for in your
surroundings in order to avoid any of/most of the above
illnesses.
2. A doctor/nurse/health-worker is exposed to more sick people
than others in the community. Find out how she/he avoids
getting sick herself/himself.
3. Conduct a survey in your neighbourhood to find out what the
three most common diseases are. Suggest three steps that could
be taken by your local authorities to bring down the incidence
of these diseases.
4. A baby is not able to tell her/his caretakers that she/he is
sick. What would help us to find out
(a) that the baby is sick?
(b) what is the sickness?
5. Under which of the following conditions is a person most likely
to fall sick?
(a) when she is recovering from malaria.
(b) when she has recovered from malaria and is taking care of
someone suffering from chicken-pox.
(c) when she is on a four-day fast after recovering from malaria
and is taking care of someone suffering from chicken-pox.
Why?
6. Under which of the following conditions are you most likely to
fall sick?
(a) when you are taking examinations.
(b) when you have travelled by bus and train for two days.
(c) when your friend is suffering from measles.
Why?
188 SCIENCE