Medieval Leech Collectors

Welcome to History’s Worst Paycheck, where we dig into the dirtiest, most dangerous, and downright worst jobs in human history.

Picture this: You're standing knee-deep in cold, stagnant swamp water. The mud squishes between your toes, insects buzz around your head, and suddenly—you feel a slimy creature latch onto your leg. Then another. And another. You don't scream. You don't run. Instead, you smile weakly, knowing you've just made a few pennies.

Congratulations: You're officially a medieval leech collector.

In medieval Europe, doctors believed in the theory of humorism, a medical concept suggesting our bodies were governed by four fluids, or "humors"—blood, phlegm, black bile, and yellow bile. When someone fell ill, these doctors blamed an imbalance of humors, usually too much blood. The solution? Drain it. And the easiest way to do that was with nature's own blood-sucking marvel: the leech.

But before these little parasites could be slapped onto patients, someone had to gather them. Enter the leech collectors: often poor women or desperate individuals who would wade into marshes, bogs, and swamps, allowing leeches to latch onto their legs and feast until fully gorged. Once sufficiently swollen with blood, they'd carefully remove the leeches, dropping them into clay jars and hoping not to pass out from the blood loss.

The work was grueling, the conditions terrible, and the pay insultingly low. Collectors frequently suffered from anemia, dizziness, infections, and occasionally—complete blood loss. Yet, their role was vital, fueling a medical craze that saw tens of millions of leeches used annually across Europe.

But how did collectors cope with losing blood every single day? Could you really make a living off swamp parasites? And what happened when medieval doctors finally realized they'd made a terrible mistake?