Disease?

The normal functioning of the body distributed by any reason is called disease. Disease are divided into main two types:-
1: congenital-- congenital disease are unborn.
2: acquired-- acquired disease are developed after the birth. Communicable or infectious and non-communicable or non-infectious are the types of acquired disease.
Disease causing agent are physical, chemical, mechanical or biological substances. Biological agents are viruses, bacteria, fungi, protozoans, trematodes, cestodes, nematodes. Some arthropods act as vectors like mosquitoes, flies. Chemical agents are pollutants, alcohol, tobacco, urea and hormones.
The transmission of diseases occur by two methods viz. direct transmission and indirect transmission. Direct transmission can ouccer from mother to child. Indirect transmission of diseases can occur through pathogen.