Which ancient physician is credited with identifying the four humours?

• A. Galen
• B. Hippocrates
• C. Avicenna
• D. Aristotle

Answer: (B)

Humoral theory centers on the idea that health depends on a balance of four bodily fluids: blood, phlegm, yellow bile, and black bile. Hippocrates is credited with identifying and naming these four humours, establishing the foundational view that illness comes from an imbalance among them. His work set the stage for how medicine approached disease for centuries. Galen later expanded and systematized the theory, applying it broadly to explain many conditions, but the original identification comes from Hippocrates. Avicenna contributed to medical knowledge and helped transmit earlier ideas, but did not originate the four-humours concept, and Aristotle was a philosopher whose focus was more on natural philosophy than on establishing humoral medicine.