Cholesterol is a waxy substance produced by the liver and consumed through food. High cholesterol does not cause symptoms but can build up in arteries and lead to heart disease over time. A fasting blood test measures total cholesterol, "bad" LDL cholesterol, "good" HDL cholesterol, and triglycerides. Lifestyle changes like a low-fat diet, exercise, weight loss, and quitting smoking can help lower cholesterol levels, and medications may be needed if levels remain high despite lifestyle modifications. Long-term management of cholesterol is important for reducing the risk of heart attack, stroke, and other cardiovascular diseases.