Answer:
It's interesting you asked that. During that era, it was widely believed that the health and well-being of different parts of the body were controlled by four humors, which were fluids in the body. These four humors were blood, yellow bile, black bile, and phlegm. It was believed that a person's overall health was determined by the balance of these four humors in the body. The concept was known as humorism and was prevalent in medieval medical theory.