Page "Bloodletting" Paragraph 28

One reason for the continued popularity of bloodletting ( and purging ) was that, while anatomical knowledge, surgical and diagnostic skills increased tremendously in Europe from the 17th century, the key to curing disease remained elusive, and the underlying belief was that it was better to give any treatment than nothing at all.

The psychological benefit of bloodletting to the patient ( a placebo effect ) may sometimes have outweighed the physiological problems it caused.

Bloodletting slowly lost favour during the 19th century, but a number of other ineffective or harmful treatments were available as placebos — mesmerism, various processes involving the new technology of electricity, many potions, tonics, and elixirs.