Hippocrates and the Four Humors
Hundreds of years ago, back in the fifth century BCE, the philosopher Hippocrates (hip-aw-crate-tees) came up with an idea. He said that the human body was made up of four liquids, or humors, that balanced the body. If one of the humors was out of balance, then a person would start to act differently or feel sick. The humors also came to be associated with certain temperatures and seasons, and there were specific methods used to rid the body of the excess humors and bring the body back into order.
Blood
Yellow bile
This humor was said to be found in the gallbladder, poop, and vomit, and too much of it caused a person to have a short temper and be aggressive. Yellow bile was thought to be more common during summer when the weather was hot and dry.
Black bile
Too much black bile was associated with a moody and grumpy personality and said to cause tummy problems, sadness, and body aches. This humor was often associated with autumn.
Phlegm
People with too much phlegm were thought to be low in spirit, forgetful, sensitive to cold, and have white hair. Phlegm was thought to come from sweat, saliva, puss, and mucus and was thought to be more common in the winter months.