The theory of the four humors was based upon the ideas of Greek philosophers like Aristotle and used by Greek doctor Hippocrates to diagnose illnesses and suggest treatments
The theory of the four humors
The body was composed of four liquids or humors linked to the four elements and the seasons: blood, phlegm, black bile, and yellow bile
Fluids representing the four humors
Blood, phlegm, black bile, yellow bile
Balance of humors
If all humors in the body are balanced, a person is well; if there is too much or too little of a particular humor, the person becomes unwell
Seasons and illnesses
Certain illnesses seem to be more common at different times of the year, possibly related to the balance of humors
The theory of the four humors attempted to explain how illness was caused without relying on supernatural ideas like evil spirits and God
Cold symptoms
Shivers, lots of phlegm and snot
Cold symptoms
Ancient Greeks would attribute it to too much phlegm and suggest treatments to balance the humors, such as extracting phlegm or breathing in vapors
Ancient Greek medical beliefs
Too much phlegm causing lots of phlegm and snot, treatment involves extracting phlegm to balance humors, methods like blowing nose or inhaling vapors
Too much blood causing rash and fever, treatment involves bleeding the patient to restore balance of humors
Too little black bile causing constipation, treatment involves eating laxative foods to induce deliberate diarrhea
Imbalance in humors
Causes illness
The theory of the four humors includes blood, black bile, yellow bile, and phlegm
Illness is believed to result from imbalances in the humors
The theory of the four humors was a rational explanation of illness, although incorrect
Treatments based on the four humors treated symptoms, not the cause of the disease
Preventions based on the four humors were either common sense or potentially harmful, such as bleeding
The theory of the four humors remained one of the most widespread theories of the cause of disease for centuries
Progress of the idea of the four humors
Represented progress in ancient Greek times, continuity in medieval times, and regress in the Renaissance and beyond