Cholesterol is a type of fat found in your body. Your total cholesterol includes LDL (low-density lipoprotein) and HDL (high-density lipoprotein) cholesterol. LDL is called “bad” cholesterol because it can build up in the walls of your arteries and form plaque. Plaque build-up in the arteries can reduce blood flow and increase your risk of heart disease. HDL (high-density lipoprotein) cholesterol is also known as “good” cholesterol because it is thought to help remove “bad” cholesterol from the body.