Why Did Medieval People Cover Themselves in Bloodsucking Leeches?

In medieval times, bloodletting was a common medical practice for treating a wide range of ailments, from headaches to leprosy. The belief was that the removal of "bad" blood could restore balance to the body and promote healing. Leeches, with their natural bloodsucking abilities, were often employed for this purpose. Doctors would place the leeches on the patient's skin, typically near the affected area, and allow them to feed. The leeches would then be removed once they were engorged with blood, leaving the patient with small wounds that would bleed for a while, further purging the "bad" blood. While this practice may seem gruesome by modern standards, it was widely accepted in medieval times and often seen as a beneficial and necessary medical treatment.