How are the four humors linked to the seasons?

The four humors—blood, phlegm, yellow bile, and black bile—were historically associated with the seasons in ancient and medieval medicine. Blood was linked to spring, representing renewal and vitality; phlegm to winter, symbolizing cold and dampness; yellow bile to summer, reflecting heat and dryness; and black bile to autumn, associated with melancholy and decay. This connection illustrated how bodily health and temperament were thought to be influenced by seasonal changes. Thus, imbalances in humors were believed to result from seasonal variations, affecting both physical and emotional well-being.