Humorism is an ancient medical theory that suggests human health is governed by four bodily fluids, known as humors: blood, phlegm, black bile, and yellow bile. Each humor is associated with specific temperaments and health conditions. The balance among these humors was believed to be essential for maintaining good health, and an imbalance could lead to illness. The concept of humorism dates back to ancient Greece, particularly to the work of Hippocrates and later Galen. This theory influenced medical practices for centuries, shaping how doctors diagnosed and treated patients. Although humorism has been largely replaced by modern medicine, it laid the groundwork for understanding human physiology.