CBSE Class 9 Biology Why Do We Fall Ill?
Health and DiseaseHealth is defined as a state of complete physical, mental and social well-being.
Major factors affecting health are Nutrition, Physical activity, Personal hygiene, clean environment, and mental stress.
External factors that cause disease are pathogens, toxic pollutants, and Poor food and dietary choices.
Kinds of DiseasesAn acute disease can begin rapidly but can be mild, severe, or even fatal. A chronic disease lasts for a long time.
A non-infectious disease or non-communicable diseases can not be transmitted from one person to another.
Infectious diseases spread through air, water and food or direct physical contact.
Treatment and Prevention of DiseasesAn infectious disease can be treated by either Symptomatic treatment or by killing the infectious microbe.
For killing a microbe its specific biochemical pathway is targeted.
Vaccination or immunization is the administration of Vaccine to produce immunity to a disease.