Bloodletting is a medical practice that sounds obviously wrong to us now, but for centuries was the height of medical wisdom. Long before anyone understood how diseases and the body’s circulation worked, healers believed that blood was at the center of many illnesses. And so they turned to knives and leeches, with the conviction that letting blood flow out of the body could draw sickness out with it. Yet it was a dark and troublesome business, and many became rich from it.
But how, exactly, did bloodletting spread across society? And what harm did it actually do? Click on to find out.