Medieval barbers played an important role in early medicine. Unfortunately, they were constrained by the severely limited medical knowledge of the day. They received far less training than Medieval surgeons, who were educated at universities; as a result, a barber’s practice was largely limited to bloodletting and tooth extraction.
Bloodletting was the intentional removal of blood from the body in an effort to restore balance among the four humors: yellow bile, black bile, blood and phlegm, which correlated with the four elements of fire, earth, air and water, respectively. If the patient was believed to have too much “bad” blood, blood was removed, either by slicing the skin or through the application of leeches, to restore the balance.
The treatment of toothaches was similarly misinformed. A common cure involved burning a candle very close to the tooth; the heat would theoretically drive the worms thought to cause the ache to leave the tooth and jump into a cup of water held below the patient’s mouth. When that treatment failed, the tooth was extracted with pliers, without anesthetic.
The iconic barber pole, in fact, was symbolic of the practice; blood-soaked bandages were hung on the barber pole to dry, and wind blowing the bandages around the pole gave rise to the diagonal striped pattern eventually painted on modern barber poles.