The four humours

Humorism, or humoralism, was a system of medicine detailing the makeup and workings of the human body, adopted by Ancient Greek and Roman physicians and philosophers, positing that an excess or deficiency of any of four distinct bodily fluids in a person—known as humors or humours—directly influences their temperament and health. It is also present in the Indian Ayurveda system of medicine.

The humoralist system of medicine was highly individualistic, for each individual patient was said to have their own unique humoral composition. Moreover, it resembled a holistic approach to medicine as the link between mental and physical processes were emphasized by this framework. Ayurveda, which is known to have been practiced in the 6th century C.E, names three elemental substances, the doshas (called Vata, Pitta and Kapha). Ayurveda is still widely practiced in India. From Hippocrates onward, the humoral theory was adopted by Greek, Roman and Islamic physicians, and became the most commonly held view of the human body among European physicians until the advent of modern medical research in the nineteenth century. The concept has not been used in medicine since then.

The four humors of Hippocratic medicine are black bile (Greek: μέλαινα χολή, melaina chole), yellow bile (Greek: κίτρινη χολή, kitrini chole), phlegm (Greek: φλέγμα, phlegma), and blood (Greek: αἷμα, haima), and each corresponds to one of the traditional four temperaments. A humor is also referred to as a cambium (pl. cambia or cambiums).

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