Cholesterol is a fat-like substance that is made by your body. It is also found in foods that come from animals, like meats, eggs and milk products. Your body needs some cholesterol to stay healthy, but it makes all the cholesterol it needs. If the cholesterol in your blood becomes too high, it can build up on the inside of your arteries, which carry blood to your heart and throughout your body. If arteries are clogged with this build up, blood flow can be cut off and a heart attack or stroke may occur.