Page 140 - Health, Population and Environment Education 10

7.2 Types of Diseases
We suffer from various diseases such as fever, diarrhoea, pneumonia, cancer, tuberculosis,
asthma, heart attack, polio, common cold, etc. Some diseases transmit from one person
to another and others do not. On this basis, diseases are mainly of two types. They are as
follows.
1. Communicable diseases
2. Non-communicable diseases

1. Communicable Diseases

Those diseases which transmit from infected person to another are called communicable
diseases. For example, common cold, diarrhoea, dysentery, AIDS, rabies, chicken pox,
typhoid, cholera, tuberculosis, measles, mumps, etc.

Fig: 3
Tuberculosis AIDS Mumps

Communicable diseases are mainly caused due to infection of micro-organisms. The
microbes of a communicable disease transmit from the infected to a healthy person by
various modes. Direct contact with the infected person, use of personal materials of the
patient, contaminated food, water, air, etc., blood of infected person, organ transplantation,
etc. are some of the common modes of transmission of communicable diseases.
Communicable diseases also transmit from one person to another by means of vectors
like mosquito, bug, flies, lice, mites, ticks, etc. For example, mosquitoes transmit diseases
like malaria, filariasis, encephalitis, meningitis, yellow fever, etc. Similarly, rabies is
transmitted due to bite of rabid animal and so on.
When micro-organisms enter our body, they increase their number and weaken our
immunity. When the immune system of human body becomes weak, symptoms of the
disease are seen.

2. Non-communicable diseases
The diseases which do not transmit from one person to another are called non-
communicable diseases. For example, problem of uric acid, asthma, heart diseases,
obesity, marasmus, scurvy, kwashiorker, rickets, cancer, etc.

140 GREEN Health, Population and Environment Education Book-10