chapter  2
36 Pages

Human diseases: Causes and reasons

One of the main types of disease in humans is infection which is usually caused by microorganism’s assault in the human body. This term, infection, broadly refers to any abnormal condition of the human body that impairs normal function of the body. Generally, this term is used to denote specic infectious diseases, which are clinically evident diseases resulting from the presence of pathogenic microorganisms such as viruses, bacteria, fungi, protozoa, multicellular parasites, and also due to aberrant proteins known as prions. The infection that does not produce any clinically evident impairment of normal functioning is not considered a disease. Diseases which are caused by noninfectious means are called

anoninfectious disease which includes cancer, heart disease, and genetic disease as a few examples.