In this , there is a search for cause of disease . The people who are risk are identified , control of spread is determined and prevent it from happening again.

Epidemiology include the areas of disease causation , outbreak investigation, transmission, forensic epidemiology and comparison of treatment effects such as clinical trials.

Epidemiologic studies are of two types namely experimental and observational.

Epidemiology is multi-disciplinary science as health is multifaceted and related to biological science . It deals with etiology or causes of disease to determine the extent of disease and to study progression of disease.