What is the study of the causes of disease called?

• A. Etiology
• B. Pathology
• C. Nosology
• D. Physiology

Answer: (A)

Etiology is the study of the causes or origins of disease. It asks what initiates a disease, whether that’s an infectious agent, a genetic factor, an environmental exposure, or a combination of factors. Knowing the etiology helps explain why a disease occurs and guides prevention and treatment strategies. For example, the etiology of tuberculosis is infection with Mycobacterium tuberculosis, while the etiology of scurvy is vitamin C deficiency. In contrast, pathology is about the tissue and organ changes caused by disease, physiology studies how normal body systems work, and nosology is the system for classifying diseases.