You will need a blood test to check whether you have high cholesterol.

• A total cholesterol test measures whether your cholesterol is high or low. You can have this test done at any time, even if you recently had a meal or snack.
• A lipoprotein analysis is a more thorough test. It measures your total cholesterol as well as your LDL, HDL, and triglyceride levels. It is called a fasting test because you are not supposed to eat for 9 to 12 hours before having your blood drawn.
• A direct LDL test measures your LDL level only. You can have this test done at any time, even if you recently had a meal or snack.

Although knowing your total cholesterol level is important, a lipoprotein test will help your doctor make certain decisions about your treatment. Knowing the levels of your good cholesterol (HDL), bad cholesterol (LDL), and triglycerides will help your doctor decide whether to prescribe medicine right away or whether you first can try making changes in your diet and lifestyle to lower your cholesterol.

The following will help you understand the results of your test:

During your doctor visit, it will be important to discuss other things that increase your risk for heart problems, such as smoking, diabetes, high blood pressure, and a family history of high cholesterol and heart attack.

You may need other tests to determine whether another health problem, such as low thyroid, is causing your high cholesterol. Some medicines may also cause high cholesterol, so it is important to tell your doctor about everything you take.

Along with your cholesterol levels, your doctor will use this information to determine your risk for coronary artery disease (CAD) and heart attack. If you have a high risk of heart disease, or if you already have heart problems, your doctor will be more likely to prescribe medicine. For more information, see the topic Coronary Artery Disease.

If you have high cholesterol or high blood pressure, you should get tested regularly for diabetes. Studies show that finding and treating diabetes early can lower the risk of heart attack.²

The American Heart Association (AHA) and the U.S. Centers for Disease Control and Prevention (CDC) recommend C-reactive protein (CRP) testing for some people who are at risk for getting coronary artery disease. There are two types of CRP tests: the older CRP measurement and a newer, high-sensitivity CRP, often called cardiac CRP. The high-sensitivity test helps find out the chances of a having a sudden heart problem, such as a heart attack.