In the earlier mentioned book, survival of the sickest, Dr. Moalem says that surely blood letting must have conferred some benefit since it was so widespread and practiced for so long.
People resorted to drilling holes in peoples heads, bloodletting and leeching, arsenic, incantations, and a host of balms and salves that could work… but could also ultimately kill a person faster than the pathogens would.
Another popular remedy was bloodletting, which was belief that drawing out bad blood that caused illness would then be restored by good blood, with the most popular method of this being with leeches.
On the other hand, the belief that bloodletting is a great way to cure all illnesses is an untrue belief that leaves us powerless in actually curing them.
Even today, we still use urine to diagnose people, but we don't usually recommend bloodletting, which was the most common treatment of the middle ages.
These categories are animal cures, medicines such as potions, fumigation, bloodletting, and pastes, flight from infected areas and persecution of marginalized communities, religious cures, and quarantine.
One study showed therapeutic blood letting improved biomarkers for patients with non-alcoholic fatty liver disease, a condition that commonly appears with diabetes.
So, the rusting long distance runner Aaron Gordon had his life saved and his health returned to normal with one of the oldest medical practices — blood letting.