Cholesterol levels are a blood test that measures the amount of cholesterol in the blood. Cholesterol is a type of fat that is produced by the liver and found in certain foods, and it is important for the body’s normal functioning. However, too much cholesterol in the blood can increase the risk of heart disease and stroke. The test typically measures three types of cholesterol: high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides. HDL is considered “good” cholesterol because it helps remove LDL cholesterol from the arteries, while LDL is considered “bad” cholesterol because it can build up on artery walls and lead to blockages. Triglycerides are another type of fat in the blood that can contribute to heart disease risk. A healthcare provider may recommend cholesterol testing as part of a routine physical exam or to help diagnose or monitor conditions such as high blood pressure, diabetes, or heart disease.