During the Medieval time period, few advances were made in the field of medicine and surgery. The belief in humors affecting ones health during the Middle Ages was responsible for the way health care was carried out.
Practitioners in Medieval Europe believed in the existence of four humors: sanguine, choler, phlegm, and melancholy. The physicians thought that illness was caused, primarily, by an imbalance of the humors (Wallace).
Each of the four humors was given specific qualities. Choler was dry and hot, melancholy was dry and cold, sanguine was moist and hot, and phlegm was moist and cold. Another property sometimes associated with the humors was color. Such as red for sanguine, and yellow for choler. This association of color and humors eventually became known as the Doctrine of Signatures which taught that "the color of flowers and other properties of plants indicated their usefulness in treating particular diseases” (Wallace). One example of this would be using yellow buttercups to control choler, to cure jaundice (Wallace).
The physician and practitioners believed that "balance of humors in humans was achieved by diet, medicines, and phlebotomy” (Krzywicka). Changing diet was very popular in the lower classes while "real” medicine and phlebotomy were reserved for people of higher social standing (Krzywicka).
Eating habits of an individual in Medieval Europe depended greatly on his financial status and, many times, his geographic location. When the change of diet was used to balance humors, the Doctrine of Signatures was put into use. For example, if one had too much sanguine in his system, he would give up foods red in color until everything was back in balance (Krzywicka). .
If a change of diet did not suit the patient, medicine would be administered. The type of medicine used would depend entirely on the ill person's social class. Someone of an upper class would get a prescription from a formerly trained physician where as someone belonging to a lower class would seek help from a "folk” doctor (Krzywicka).