Preventive medicine seeks to reduce the incidence of disease by modifying the environmental or behavioral factors that caused the illness in the first place.

Originally, preventive medicine was largely concerned with understanding and preventing infectious disease. Today, however, its scope has widened. The aim of preventive medicine is to preserve good health; to prevent disease, injury, and disability; and to facilitate early diagnosis and treatment of illness.

Preventive medicine has become a very diverse and challenging medical specialty. Preventive medicine physicians are trained in the sciences of epidemiology, biostatistics, environmental and occupational health services, administration, as well as clinical prevention. They are uniquely qualified to work with both individuals and the community to promote health and prevent disease, initiating programs in infectious disease prevention and control, sexually transmitted diseases, and in chronic disease prevention. They use scientific methods to identify health hazards in the workplace and...