Bloodletting is one of the oldest forms of medicine performed.
In the fifth century BC having someone bleed was thought to let out overabundances in the blood that should be let out.
Later and into the nineteenth century the practice would be recommended by surgeons and often carried out by barbers. The modern day red and white barber pole is a traditional reminder of the days when a barber would draw blood. Bloodletting carried on into the twentieth century.
Although bloodletting isn't seen in modern medicine, leeches still have a place in the hospital. They are best used for assisting with certain types of blood circulation issues.