2. ‘HEALTH IS WEALTH’. Health is wealth as this well known Adage says good health considered to be The greatest wealth. In living things diseases are caused by various factors. IN this unit you will learn the following; 1.Nature and cause of diseases. 2. Immunisation. 3. Importance of Hygiene..

3. When the human body lacks adequate nourishment, it becomes weak and is Easily susceptible to infectious diseases. To Protect ourselves from infections, we should Get vaccinated.This preventive measure is Known as immunisation. The majority of the diseases are caused By virus & bactriea, which are called pathogens. Diseases like cholera, plague, I

4. 1.PRIMARY IMMUNISATION : The administration of one or more Than one type of vaccine by injecting it Into body, to create the necessary resistance Is called primary immunisation. 2. SECONDARY IMMUNISATION: By administering the vaccine again, A short time after the primary immunisation, Permanent resistance is developed. This is Called secondary immunisation.

5. The combined effect of the well being of mind, Body and society is total health such a health human being performs his daily duties exceedingly Well. His relationship with his family and his interaction With society will be harmonious. A person can lead a healthy life only when he Keeps his food, clothes, shelter and the surroundings Clean.