2. What is a disease?
A disease is an abnormal condition affecting the body of an organism. It is
often construed to be a medical condition associated with specific symptoms
and signs. It may be caused by external factors, such as infectious disease, or
it may be caused by internal dysfunctions, such as autoimmune disease.
3. Obesity
• Obesity is a medical conditions in which excess body fat has accumulated to the extent
that it have an adverse effect on health, leading to reduced life expectancy and/or
increased health problems. Body mass index(BMI), a measurement which compares
weight and height, defines people as overweight (pre-obese) if their BMI is between 25 and
30 kg/m2, and obese when it is greater than 30 kg/m2.[3obesity increases the likelihood of
various diseases particularly heart disease type 2 diabetes ,obstructive sleep apnea certain
types of cancer, and osteoarthritis. Obesity is most commonly caused by a combination of
excessive food energy intake, lack of physical activity, and genetic factors, although a few
cases are caused primarily by genes, endocrine disorders, medications or psychiatric
illness. Evidence to support the view that some obese people eat little yet gain weight due
to a slow metabolism is limited; on average obese people have a greater energy
expenditure than their thin counterparts due to the energy required to maintain an
increased body mass.
• Obesity is a leading preventable cause of death worldwide, with increasing prevalence in
adults and children, and authorities view it as one of the most serious public health
problems of the 21st century. Obesity is stigmatized in much of the modern world
(particularly in the Western World), though it was widely perceived as a symbol of wealth
and fertility at other times in history, and still is in some parts of the world.
4. Diabetes
• Diabetes (diabetes mellitus) is classed as a metabolism disorder. Metabolism refers to the way our
bodies use digested food for energy and growth. Most of what we eat is broken down into glucose.
Glucose is a form of sugar in the blood - it is the principal source of fuel for our bodies.
When our food is digested the glucose makes its way into our bloodstream. Our cells use the
glucose for energy and growth. However, glucose cannot enter our cells without insulin being
present - insulin makes it possible for our cells to take in the glucose.
Insulin is a hormone that is produced by the pancreas. After eating, the pancreas automatically
releases an adequate quantity of insulin to move the glucose present in our blood into the cells,
and lowers the blood sugar level.
A person with diabetes has a condition in which the quantity of glucose in the blood is too elevated
(hyperglycemia). This is because the body either does not produce enough insulin, produces no
insulin, or has cells that do not respond properly to the insulin the pancreas produces. This results
in too much glucose building up in the blood. This excess blood glucose eventually passes out of the
body in urine. So, even though the blood has plenty of glucose, the cells are not getting it for their
essential energy and growth requirements.
• So in other simple words, diabetes is a disease in which our body is not able to control de levels of
sugar in our blood system. Diabetes is closely related to obesity and is one of the modern day
diseases in our society.
5. AIDS
• Acquired immune deficiency syndrome or acquired immunodeficiency
syndrome (AIDS) is a disease of the human immune system caused by the
human immunodefiency virus(HIV). The illness interferes with the immune
system making people with AIDS much more likely to get infections,
including opportunistic infections and tumors that do not affect people
with working immune systems. This susceptibility gets worse as the
disease continues.
• HIV is transmitted in many ways, such as anal, vaginal or oral sex, blood
transfusions, contaminated hypodermic needles, exchange between
mother and baby during pregnancy, childbirth, and breastfeeding. It can
be transmitted by any contact of a mucous membrane or the bloodstream
with a bodily fluid that has the virus in it, such as the blood, semen,
vaginal fluid, preseminal fluid, or breast milk from an infected person.
