Which branch of medicine focuses on the causes, distribution, and control of disease in populations?

• A. Epidemiology
• B. Pathology
• C. Immunology
• D. Pharmacology

Answer: (A)

Epidemiology examines how and why diseases arise in populations and how to prevent their spread. It looks at causes, distribution, and determinants across groups, asking who is affected, where and when cases occur, and which factors increase risk. This field uses measures like incidence and prevalence, explores patterns by age, location, or behavior, and relies on study designs that track people over time or compare groups to identify associations. The ultimate goal is to guide public health actions such as vaccination programs, screening, and policy changes to reduce disease burden.

For contrast, pathology focuses on disease processes at the tissue or cellular level, immunology on how the immune system responds, and pharmacology on drug actions and effects.