INTRODUCTION/DEFINITIONS :
Health is a state of being well enough to function well physically, mentally and socially.
Disease literally means being uncomfortable.
Tissues make up physiological systems or organ systems that carry out body functions.
The musculoskeletal system, which is made up of bones and muscles, holds the body parts together and helps the body move.
Some diseases last for only very short period of time and these are acute diseases.
Any diseases that causes poor functioning of some part of the body will affect our health.
Diseases where microbes are the immediate causes are called infectious diseases.
The same drug will not work against the microbe belonging to a different group.
Many bacteria, for example, like a cell wall protect themselves. The antibiotic penicillin blocks the bacterial processes that build the cell wall.
An infection like HIV, that comes into the body via the sexual organs, will spread to lymph nodes all over the body.
The immune cells manage to kill off the infection long before it assumes major proportions.
It is difficult to develop vaccines against the diseases caused by viruses. Viruses are very specific to hosts. They have no metabolic machinery of their own. Viruses live and multiply only in the living cells.
D.P.T. is a vaccine which is three-in-one. D = Diphtheria, P= Pertussis (whooping cough), T = Tetanus.
In nearly all the infections of the human body, there is a rise in body temperature, an increased rate of heart beat, increased frequency of respiration, dry tongue, poor appetite, concentration of urine and changes in white blood cells circulating the blood.
One who harbours germs of a disease but does not suffer from the disease is termed as a carrier of the disease.