HDL stands for high-density lipoprotein and is used to describe one of the two types of cholesterol in the body. HDL cholesterol is known as the "good" cholesterol, while low-density lipoprotein cholesterol, or LDL cholesterol, is known as the "bad" cholesterol.
The higher the level of HDL cholesterol in the body, the lower the amount of LDL cholesterol present in the blood. By increasing the amount of HDL and reducing the level of LDL, a person's risk of heart disease may be lowered. HDL collect excess LDL from the blood and deliver it to the liver, where it is broken down.