Barber-Surgeon
Beginning in ancient Egypt and continuing through the 1800s, barbers were charged with more than just cutting hair: They also extracted teeth, set fractures, removed hangnails, drained blood (the most common surgical procedure for nearly two millennia), and even amputated limbs. Many had no formal training and learned their trade though apprenticeship under an experienced barber-surgeon; few could read. Fun fact about the red and white pole that still signifies a barber shop: The colors were chosen to represent blood and the napkins used to mop it up.
Leech Collector
Thought to restore balance and order to the body, bloodletting is believed to have originated in ancient Egypt. It became the go-to treatment for a panoply of ailments in medieval Europe. When a papal edict in 1163 forbade priests and monks, who often provided medical treatment, from shedding blood, bloodletting duties were transferred to barbers, who carried them out until bloodletting fell out of fashion in the late 1800s. But, surgeon-barbers couldn't do their jobs without the all-important leech collector: Leeching was the most popular bloodletting technique between 1830 and 1850, and diligent leech collectors in early modern Europe (who were often poor and female) stood in ponds and allowed leeches to attach to their bare skin before plucking them off and selling them. (They may have believed they were receiving free medical treatment, but leech collection sounds like a grim day job nonetheless.) While your doctor won't use a leech at your next appointment, a 2012 study indicated that bloodletting may actually offer cardiovascular benefits to obese patients with metabolic syndrome. This medical fad may not be over just yet — and if you want to try it for yourself, head to Brooklyn.
Medicine Man
In the late 1800s and early 1900s, "medicine men" roamed the country hosting pop-up shows where they hawked their wares: magical panaceas purported to cure everything from tuberculosis to STDs to PMS to cancer. The problem, of course, is that these "remedies" were by and large ineffective, harmful, or even lethal. Popular ingredients included alcohol, morphine, codeine, and cocaine. Tragically, many of these treatments were advertised for babies and children, with sometimes-fatal results.
Plague Doctor
If the plague didn't kill you, the fright from seeing a costumed plague doctor hovering over your bedside might have. These "doctors," who were generally not professionally educated, wore beaked masks filled with perfume (the aroma was thought to protect the wearer from sickness) and carried canes they used to remove patients' clothing — and, somehow, check patients' pulses. These "medical" practitioners were in highest demand during the Bubonic Plague that killed half of Europe's population in the 1300s; Europe was pretty much willing to try anything at that point, including cane prods from untrained men dressed like birds.
Alchemist
Alchemy can be traced back to the Greco-Roman world. It wasn't only about transforming everyday substances into gold; it also attempted to innovate early forms of medicine. Ancient Chinese alchemist Ko Hung, for example, proposed that men drink cinnabar combined with raspberry juice to treat infertility, while mercury became a popular treatment for syphilis in the 1500s (all the way through the early 1900s). Sadly, like so many alchemy-based remedies, neither of these treatments appear to have done the trick.
Toad Doctor
In 18th- and 19th-century Britain, toads were believed to cure all manner of ills when worn in a bag around one's neck. An 1899 report published by The Folklore Society details the activities of a local toad doctor: "He used to amputate the limb of a living frog, and…put the leg into a muslin bag and suspended it round the neck of the patient, inside the clothing, allowing to to rest on the chest. If the patient felt a twitching and received a shock, the cure was said to be accomplished."