Bloodletting originated in ancient Egypt. It then spread to Greece, where physicians believed that all illnesses stemmed from an overabundance of blood, or plethora.

In medieval Europe, bloodletting became the standard treatment for various conditions, from plague and smallpox to epilepsy and gout. Practitioners typically nicked veins or arteries in the forearm or neck, sometimes using a special tool featuring a fixed blade and known as a fleam. If you got lucky, leeches might perform the gruesome task in place of crude instruments.