This document defines diseases and different types of diseases. It explains that a disease is a medical condition that stops the body from working normally. It distinguishes between communicable and non-communicable diseases, with communicable diseases being able to spread from person to person through conditions like the flu, COVID-19, or malaria. Meanwhile, non-communicable diseases cannot pass between individuals and include conditions like diabetes, epilepsy, or hypertension. The document also differentiates between acute and chronic diseases, with acute diseases lasting a short time under three months, while chronic diseases can last much longer, even a lifetime.

1. Grade 12
Diseases of the body systems
Academic Year 2021/2022 – Term 1

2. Unit-2 Lesson no. 2.1
Lesson name: What are diseases?

3. Learning
outcome
By the end of the lesson, learners will be
able to:
explain the difference between communicable
and non-communicable diseases.

4. Keywords
• communicable disease – an infectious disease that can be
passed from one person to another
• acute - a disease or disorder that lasts a short amount of
time, usually less than three months
• chronic - a disease or disorder that lasts three months or
more
• sign - something that can be observed by other people, such
as a skin rash or a
cough
• symptom- a feeling, or physical change experienced by the
patient, such as pain

5. • Diseases may cause:
• Pain in the body
• Parts of the body to stop working
• Death
A disease is a medical condition that
stops the body from working normally.

6. Communicable
Diseases can be communicable or non-communicable
Non-communicable
• Can be spread from one person to another.
• Examples include:
• Flu
• COVID-19
• Gastroenteritis
• Malaria
• Cannot be passed from one person to
another.
• Examples include:
• Epilepsy
• Hypertension
• Diabetes
• Multiple sclerosis

7. Acute
Diseases can be acute or chronic
Chronic
• Last a short length of time, usually less than
three months.
• Examples include:
• Flu
• COVID-19
• Gastroenteritis
• Pneumonia
• Last a long time, sometimes even the length
of a person’s life.
• Examples include:
• Asthma
• Allergies
• Diabetes
• Multiple sclerosis

8. A journey through the human body

9. Do you remember these from grade 11?

10. Learning
outcome
By the end of the lesson, learners will be
able to:
explain the difference between communicable
and non-communicable diseases.

11. Conclusion
Questions
Recap