To restore bodily harmony, the doctor would simply cut open a vein and drain some of their vital fluids into a receptacle. In some cases, leeches were even used to suck the blood directly from the skin. It could easily result in accidental death from blood loss.The practice finally fell out of vogue after new research showed that it might be doing more harm than good, but leeching and controlled bloodletting are still used today as treatments for certain rare illnesses.
Trepanation
It is the practice of boring holes in the skull as a means of curing illnesses. A common theory holds that it may have been some form of tribal ritual or even a method for releasing evil spirits believed to possess the sick and mentally ill. Still others argue that it was a more conventional surgery used to treat epilepsy, headaches, abscesses and blood clots.
Mercury
Mercury is notorious for its toxic properties. It was used as an elixir and topical medicine. The ancients considered it a useful ointment and alchemists prized liquid and red mercury sulfide for their supposed ability to increase lifespan and vitality. Some healers even promised that by consuming noxious brews containing poisonous mercury, sulfur and arsenic, their patients would gain eternal life and the ability to walk on water. Mercury was also used as a popular medicine for STD's. While some accounts claimed the heavy metal treatment was successful in fighting off the infection, patients often died from liver and kidney damage caused by mercury poisoning.
Animal Dung Ointments
Lizard blood, dead mice, mud and moldy bread were all used as topical ointments and dressings, and women were sometimes dosed with horse saliva as a cure for an impaired libido. Donkey, dog, gazelle and fly dung were all celebrated for their healing properties and their ability to ward off bad spirits. While these repugnant remedies may have occasionally led to tetanus and other infections, they probably weren't entirely ineffective.
Cannibal Cures
Physicians prescribed elixirs containing human flesh, blood or bone to treat headaches, muscle cramps and stomach ulcers. So-called “corpse medicine” was a disturbingly common practice. These cannibalistic medicines were thought to have magical properties. By consuming the remains of a deceased person, the patient also ingested part of their spirit, leading to increased vitality and wellbeing.