Understanding the Four Humors: A Historical Perspective

Blood - Associated with the element air and the season spring, blood was thought to be produced by the heart and liver and was connected to a person's energy and vitality.

Phlegm - Associated with the element water and the season winter, phlegm was thought to be produced by the brain and was associated with a person's calmness and intelligence.

Yellow Bile - Associated with the element fire and the season summer, yellow bile was thought to be produced by the liver and was linked to a person's anger and passion.

Black Bile - Associated with the element earth and the season autumn, black bile was thought to be produced by the spleen and was connected to a person's sadness and melancholy.