Page 5 - 2- Lesson Notes- Health and its failure; Disease and its causes

1. These diseases occur suddenly. They occur over a prolonged period.

2. They last for a shorter period. They last longer, even for a lifetime.

3. They do not cause damage to the
body. They damage the body of the patient.

4. They are not fatal. Chronic diseases are fatal.

5. E.g., common cold, jaundice, typhoid, E g., HIV, Elephantiasis, Cancer,
malaria Tuberculosis

2. Congenital and Acquired Diseases

a) Congenital diseases are physiological abnormalities present since birth. These

may be caused by –
i. Gene or Chromosomal mutations (E.g. Colour blindness, Sickle-cell anaemia,

Down syndrome, Turner syndrome)
ii. Environmental factors (E.g. Cleft palate and hare lip)

b) Acquired diseases develop after birth. These are of two types:

i. Infectious (Communicable diseases)
ii. Non-infectious (Non communicable diseases)

Difference between Infectious and Non-infectious Diseases:

Infectious or Communicable Diseases Non-infectious or Non-Communicable
Diseases
These are caused by extrinsic or external These are caused by intrinsic or internal

factors. factors.

They are caused by attack of pathogens. They are not caused by pathogens.

The diseases brought about by extrinsic or The diseases are mostly brought by intrinsic
external factors. or internal factors.

Infectious diseases can pass from diseased Non-infectious diseases cannot pass from
person to a healthy person. one person to another.