A small sample of blood will be drawn from your arm. If your doctor has ordered other tests to be run at the same time as your cholesterol test, all the samples will usually be taken at the same time. Your blood sample is then analyzed by a laboratory.
Your doctor will tell you if you should fast (avoid consuming food, beverages and medications, usually for nine to 12 hours) before your blood test. If you aren't fasting when the blood sample is drawn, only the values for total cholesterol and HDL cholesterol will be usable. That's because the amount of LDL (bad) cholesterol level and triglycerides can be affected by what you've recently consumed.
Your test report will show your cholesterol level in milligrams per deciliter of blood (mg/dL). Your doctor must interpret your cholesterol numbers based on other risk factors such as age, family history, smoking and high blood pressure.
Your LDL (bad) cholesterol levels will be needed to determine your treatment plan if your total cholesterol is 200 mg/dL or greater, or if your HDL is less than 40 mg/dL. If you weren't fasting for your first test, your doctor may need to send you for another test.
How often should I have my cholesterol checked? The American Heart Association endorses the National Cholesterol Education Program (NCEP) guidelines for detection of high cholesterol: All adults age 20 or older should have a fasting lipoprotein profile — which measures total cholesterol, LDL (bad) cholesterol, HDL (good) cholesterol and triglycerides — once every five years. This test is done after a nine- to 12-hour fast without food, liquids or pills. It gives information about total cholesterol, LDL (bad) cholesterol, HDL (good) cholesterol and triglycerides. You may need to have your cholesterol checked more often than every five years if one or more of these situations applies to you:
Your total cholesterol is 200 mg/dL or more.
You are a man over age 45 or a woman over age 50.
Your HDL (good) cholesterol is less than 40 mg/dL.
Where should I have my cholesterol checked? It's best to have your regular doctor run your cholesterol test. Overall risk factors such as your age, family history, smoking history and high blood pressure must be considered when interpreting your results — and your regular doctor is most likely to have all that information. Once you know your numbers, your doctor should recommend a treatment and prevention plan, as well as follow-up testing to make sure the plan is getting you to your cholesterol goals.
If you're admitted to the hospital for a major coronary event, your LDL cholesterol should be measured on admission or within 24 hours. However, it may take four to six weeks before your fasting lipid profile stabilizes and you can get accurate results. Your doctor will determine whether to start drug treatment at discharge.
If you have your cholesterol checked at public screenings, make sure a reputable company does the screening. Remember that your cholesterol level is just part of your overall cardiovascular risk profile, and your other risk factors must be considered. You should share the screening results with your healthcare professional so your tests can be properly interpreted, and an appropriate treatment and prevention plan developed.
The American Heart Association endorses the National Cholesterol Education Program (NCEP) guidelines for detection of high cholesterol: Everyone age 20 and older should have a fasting "lipoprotein profile" every five years. If you are not fasting when the test is done, your doctor won't be able to get an accurate lipid profile and may need to test you again. Be sure to review your test results with your doctor so you can understand and follow your treatment plan.