HDL (high-density lipoprotein) is sometimes called "good" cholesterol because it helps prevent cholesterol from building up in the arteries. HDL, which is made mostly of protein and only a small amount of fat, helps clear LDL (low-density lipoprotein), or “bad,” cholesterol from the body.

High levels of HDL appear to help protect against heart disease. A person who is at risk for heart disease may be advised to raise his or her HDL levels by eating a balanced diet, exercising and losing weight, and stopping tobacco use. In addition, medicines may be used to raise HDL levels.