bloodletting, Bloodletting equipment In A Medieval Hospice MuseumShare on Pinterest

Imagine you’re managing a health condition in the year 1349. It will be hundreds of years until the dawn of modern antibiotics. A 14th-century doctor — some trained at universities and some who were simply village herbalists — may suggest a multitude of medieval therapies to help.

One common treatment was bloodletting.

Yes, pouring out your own blood was one of the top treatments at the time.

So what was bloodletting all about, why was it practiced for more than 3,000 years, and does anyone still use it today?

Bloodletting was the name given to the removal of blood for medical treatment. It was believed to rid the body of impure fluids to cure a host of conditions.

Originally, bloodletting involved cutting a vein or artery — typically at the elbow or knee — to remove the affected blood.

Over time, specialized instruments and techniques — including the use of leeches — were developed to make more precise cuts and improve control over how much blood was removed.

Blood was typically drained until you passed out, which for most people amounted to about 20 ounces of blood.

It’s hard to say who came up with the idea of bloodletting, but there is evidence the practice was used as far back as 3,000 years ago, first by the Ancient Egyptians, then the Greeks and Romans, through the Middle Ages, and on to the Renaissance.

To understand the reasoning behind bloodletting, you have to consider the limited understanding of disease during those periods.

Around 5th century B.C., Hippocrates determined that humans existed in the realm of the four basic elements — earth, air, fire, and water — and that elements were reflected in the four “humors” in the body:

  • blood
  • phlegm
  • black bile
  • yellow bile

The humors were each connected to a particular organ and personality type, according to these ancient scholars. They believed illness came from an imbalance in these humors.

By the 3rd century A.D., bloodletting was already popular. Then, a scholar named Galen of Pergamum declared blood as the most significant humor. Bloodletting soon became standard practice for many centuries.

By the 1600s, more physicians were beginning to question the science behind bloodletting, but habit and public perception of its success kept the practice going for a few hundred more years.

In the late 1800s, a handful of physicians conducted studies that showed that bloodletting wasn’t effective.

Famous figures

Many throughout history were “treated” with bloodletting, including:

  • England’s King Charles II was relieved of about 24 ounces of blood to treat seizures. Multiple sessions of bloodletting and other therapies like enemas and mustard plasters failed to cure him. Modern scholars believe Charles II had chronic gout that led to renal failure and encephalopathy — none of which had better treatments in Charles’ time. The practice of bloodletting was not likely his cause of death but may have sped it along.
  • George Washington fell ill with a fever and sore throat in 1799 and was dead less than a day later. Evidence suggests that he died from a severe throat infection that caused fatal swelling and possibly sepsis. However, there are some historians who believe that removing 40 percent of Washington’s blood volume — about 80 ounces — in an 8-hour period was extreme and less than helpful.
Was this helpful?

Did bloodletting ever work? If by “work” you mean ending a disease process, then yes. Most of the people who died after bloodletting perished from diseases that were incurable in their time period — but bloodletting probably didn’t help.

There are actually some conditions that bloodletting may have inadvertently helped, but any improvement wasn’t from balancing the body’s humors.

Instead, any positive effect probably came from reducing blood volume or harmful components in the blood that had built up in the body.

For example, high blood pressure may have been temporarily relieved in some cases of bloodletting, simply through the reduction of blood volume. This fix, if not fatal, wouldn’t last long, though.

One of the biggest risks of bloodletting was — you guessed it — death. Blood loss on its own can cause death through hemorrhagic shock.

Low blood volume can also result in a number of dangerous symptoms like low blood pressure, trouble breathing, and loss of consciousness. Once you’ve lost 40 percent of your blood volume, there’s no guarantee that transfusions can help you recover.

Outside of the problems directly related to blood loss, bloodletting — especially using items like animal teeth or sticks — could lead to severe or even fatal infections and the transmission of bloodborne diseases.

Even as time went on and better tools were used, the practice of bloodletting was largely unregulated, with barbers even taking part in the practice.

Blood and tissue infections that go unresolved — a common occurrence before the invention of antibiotics — can progress to sepsis, an overwhelming infection response that is fatal for about 270,000 Americans each year.

Bloodletting is still a thing today as a form of alternative medicine in some parts of the world. It may be referred to as wet cupping, Ayurvedic detox, or other terms.

It’s also used as an evidence-based practice for certain serious medical conditions. In medical practice, the act of removing blood is now referred to as phlebotomy.

The term phlebotomy comes from the Greek word “phelps” or “phleb” for vein and “tomia” for cutting. Many people performed this practice throughout history, but today it’s done mainly by special technicians called phlebotomists.

Phlebotomy has a number of uses today. Mostly, blood is collected for diagnostic purposes, to collect blood or serous fluids for medical reasons, or to donate blood for transfusion to others.

In some cases, blood may be therapeutically removed, but generally only for rare conditions with specific evidence-based and scientific reasons.

These conditions include:


Hemochromatosis is a genetic disorder that affects how the body processes iron. It can lead to an overaccumulation of iron throughout the body. Today, this condition is treated with periodic blood draws to keep ferritin — the protein that stores iron — at a healthy level.

Polycythemia vera

Polycythemia vera is a stem cell bone marrow condition where red blood cells and certain white blood cells and platelets are overproduced. This can lead to dangerous blood clots. Blood may be drawn through phlebotomy to decrease the concentration of red blood cells and prevent clotting.

Porphyria cutanea tarda

Porphyria cutanea tarda causes inefficiency in how the body uses iron, resulting in dangerous iron accumulations. Iron levels may be kept in check with phlebotomy.

Postsurgical healing

Leech therapy is sometimes used, not as much for the removal of blood, but for the other substances leeches secrete while feeding, including enzymes like hyaluronidase and natural anticoagulants.

These secretions can help improve circulation and reduce necrosis in delicate postoperative tissues.

Cupping is one form of alternative medicine that sometimes uses a form of bloodletting. This therapy originated in China and uses cups suctioned to the body to control the flow of “qi,” an essential energy in the body to those who practice it.

Cupping does have some benefits, as it can increase circulation to affected areas. Increased blood flow can help reduce pain and promote cell healing. Dry cupping involves the use of suction, while wet cupping is a technique that uses both suction and controlled bleeding.

While bloodletting may sound like an ancient clinical treatment, the principle behind it is still used in some — albeit rare and more medically sound — circumstances today.

Historic bloodletting was based on a limited view of disease processes. Today, blood removal is usually done for diagnostic purposes or as an evidence-based method to remove specific amounts of blood to achieve very particular results.