Bloodletting facts for kids

Bloodletting was an old medical practice where doctors would remove blood from a patient's body. People believed it could cure diseases. This practice was very common in ancient times and the Middle Ages, but it was mostly stopped by the 19th century. Today, we know that removing blood usually doesn't help and can even be harmful. It's very different from Blood donation, which is a safe way to help others by giving blood.

For almost 2,000 years, from ancient times until the late 1800s, bloodletting was one of the most common medical treatments.

Why People Believed in It

People in ancient times followed a medical idea called Humorism. They thought the human body had four main "humors" or fluids: blood, phlegm, yellow bile, and black bile. They believed that for a person to be healthy, these humors needed to be perfectly balanced. If someone was sick, doctors often thought it was because one of these humors was out of balance.

Bloodletting was used to try and fix this imbalance, especially if they thought there was too much blood.

When Bloodletting Was Used

Doctors used bloodletting for many different illnesses. For example, they sometimes used it for hypertension, which is when a person has very high blood pressure. Removing blood could sometimes lower blood pressure for a short time by reducing the total amount of blood in the body. However, in ancient times, doctors didn't know how to measure blood pressure directly, so they didn't know if it was actually helping.

In most cases, bloodletting did more harm than good. Patients often became weaker or developed other problems because of the blood loss.

Modern Use of Bloodletting

Today, bloodletting is almost never used. However, there are a very few specific conditions where it can still help.

One such condition is Polycythemia vera. In this disease, the body makes too many red blood cells. This makes the blood thicker than normal, which can cause health problems. Removing some blood helps to reduce the number of red blood cells and make the blood thinner.

Another similar condition is called Polycythemia, which also means there are too many red blood cells. In these rare cases, bloodletting is done carefully and under modern medical supervision.

Images for kids

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  A chart showing the parts of the body to be bled for different diseases, c. 1310–20

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  Points for bloodletting, Hans von Gersdorff, Field book of wound medicine, 1517

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  Ioannis Sculteti, Armamentium Chirugiae, 1693 – diagrammed transfusion of sheep's blood

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  Scarificator

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  Scarificator mechanism

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  Scarificator, showing depth adjustment bar

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  Diagram of scarificator, showing depth adjustment

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  Bloodsticks for use when bleeding animals

See also

In Spanish: Sangría (tratamiento médico) para niños