The Four Humours

Long before lab tests or X-rays, doctors believed four bodily fluids called the humours controlled your health. If you had a fever, felt sad, or just felt “off”, it was because of your humours, apparently. 

The idea of the four humours dates back to ancient Greece, around 400 BCE. The father of medicine, Hippocrates, introduced the concept as a way to explain how the body worked. He believed the human body was made up of blood, phlegm, yellow bile, and black bile. Each humor had specific characteristics. Blood was warm and wet, phlegm was cold and wet, yellow bile was warm and dry, and black bile was cold and dry. The main theory that surrounded the humours is that a person has to keep all four in balance to have good health. 

Later, another physician named Galen expanded on this theory and connected the humours to personality. He said that your mood and behavior was controlled by your bodily fluids. Too much blood meant you were optimistic, too much phlegm meant you were calm, too much yellow bile meant you were irritable, and too much black bile meant you were melancholic.

If someone got sick, the goal wasn’t to target the disease. It was to restore the balance of the four humours, which led to some crazy treatments. Doctors would perform bloodletting, prescribe special diets, use herbal remedies, or induce vomiting. Bloodletting for example, would get rid of excess blood, restoring balance.

The idea of the humours dominated medicine for over 2,000 years and it shaped how doctors understood the human body. It lasted so long because without microscopes or advanced technology, it was practically impossible to understand how the body worked on a cellular level, and therefore, the body was explained by the humours, which were visible to the human eye. Also, figures like Hippocrates and Galen were influential in medicine and their ideas were widely respected for a long time.

Everything started to change during the Scientific Revolution when new discoveries were being made. Scientists started to learn more about anatomy and circulation, leading the idea of the humors to fall apart. By the 19th century, after the rise of the germ theory, the humoral theory was largely replaced by medical science, which showed that diseases were caused by pathogens, not an imbalance of fluids.

The idea of the humours wasn’t completely inaccurate, however. It encouraged people to look for natural explanations for disease instead of blaming the supernatural. It was one of the first steps to modern medicine, in many ways. The idea of balance still shows up in the medical world in areas like nutrition and wellness. The four humours may not be relevant to today’s time, but they still left an impact on medical history and left us amazed at what treatments looked like long ago.