Epidemiology is the study of how diseases and health conditions spread and are distributed in a population. In epidemiology, patients are viewed as members of a community, with research and analysis performed on a community level. A community can be small or large, ranging from a neighborhood to a city, all the way to an entire country or continent.
Epidemiologists gather and analyze data to make educated conclusions. For example, an epidemiologist may focus on why a disease occurred in a certain area, which factors led to the spread of disease in a certain area, and what can potentially be done to not only curb or eliminate the spread of the disease in that area but also prevent it from occurring and spreading in a different area.
Although epidemiology is generally associated with infectious diseases, the field encompasses more than just infectious diseases. Epidemiologists may focus on anything that affects public health in a pattern-based way, including:
Chronic disease epidemiology focuses on the study of chronic diseases, such as heart disease, cancer, and diabetes.
Infectious disease epidemiology investigates the causes, transmission, and prevention of infectious diseases such as influenza, HIV/AIDS, and tuberculosis.
Environmental epidemiology focuses on the study of how environmental factors, such as air pollution, water contamination, and climate change, can affect human health.
Occupational epidemiology studies how work-related factors, such as exposure to chemicals and physical hazards, can affect the health of workers.