Cholesterol and Triglycerides Tests
Why It Is Done
Cholesterol and triglyceride testing is
- As part of a routine physical exam to screen for a
- To check your response to medicines used to treat lipid
- To help determine your chances of having of heart disease,
especially if you have other risk factors for heart disease or symptoms that
suggest heart disease is present.
- If you have unusual symptoms, such as yellow fatty deposits in
the skin (xanthomas), which may be caused by a rare genetic disease that causes
very high cholesterol levels.
Cholesterol and triglyceride screening
Some health organizations recommend that everyone older than
age 20 be checked for
high cholesterol.1 Other organizations recommend cholesterol tests based on age and risk factors for heart disease.2
Talk to your doctor about when you should get a cholesterol test.
For more information, see When to Have a Cholesterol Test.
How To Prepare
Preparation depends on the test. Ask
your doctor which test you are having. You may or may not have to fast. For example, you can get a total
cholesterol test or direct LDL test at any time, even if you recently had a
meal or a snack. But if you get a test that
measures LDL and HDL, you will fast for about 9 to 12 hours.
- If your doctor tells you to fast before your test, do not eat or
drink anything except water for 9 to 12 hours before having your blood drawn.
Usually, you are allowed to take your medicines with water the morning of the
test. Fasting is not always necessary, but it may be recommended.
- Do not eat high-fat foods the night before the test.
- Do not drink alcohol or exercise strenuously before the
Many medicines may affect the results of this
test. Be sure to tell your doctor about all the nonprescription
and prescription medicines and herbs or natural substances you take.
Tell your doctor if you have had a test such as a thyroid or
bone scan that uses a radioactive substance within the last 7 days.
Talk to your doctor about any concerns you have regarding
the need for the test, its risks, how it will be done, or what the results will
mean. To help you understand the importance of this test, fill out the
medical test information form(What is a PDF document?).
How It Is Done
The health professional taking a sample
of your blood will:
- Wrap an elastic band around your upper arm to stop the flow of
blood. This makes the veins below the band larger so it is easier to put a
needle into the vein.
- Clean the needle site with alcohol.
- Put the needle into the vein. More than one needle stick may be
- Attach a tube to the needle to fill it with blood.
- Remove the band from your arm when enough blood is
- Put a gauze pad or cotton ball over the needle site as the needle
- Put pressure on the site and then put on a bandage.