Why do we fall ill

Introduction

Health is a state of complete physical, mental and social well-being.

Basic conditions for good health:

•    Proper balanced and nutritious diet.
•    Personal hygiene.
•    Clean environment and surroundings.
•    Healthy air, no pollution in the surrounding.
•    Regular exercise.
•    Proper rest.
•    Good standard of living and economic status.

Disease: when the body is not at ease i.e., comfortable then it is said to have a disease.
When there is a disease, the functioning or appearance of one or more systems of the body changes.

Disease is classified as Acute and Chronic.

Acute disease: Diseases that last for only short period of time, e.g., headache, common cold etc.
Chronic disease: Diseases that last for long time,’ are called chronic diseases, e.g., elephantiasis, tuberculosis, etc.

Causes of diseases: Immediate cause and contributory cause.

Immediate cause: The organisms that enter our body and causes disease is called immediate cause. For example, virus, bacteria, protozoa etc.

Contributory cause: The secondary factors which led these organisms enter our body are called as contributory cause. For example, dirty water, unclear
surroundings, contaminated food, improper nourishment, poverty, poor standard of living etc.
Diseases may be due to infectious and non-infectious causes.

(a) Infectious causes: Diseases where microbes are the immediate causes are called infectious diseases. The infection spreads from one person to another.

(b) Non-infectious causes: Some diseases that do not spread in the community, but remains internal are called non-infectious diseases. Example, cancer, genetic abnormalities, high blood pressure etc.