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Cholesterol and Triglycerides Tests

Test Overview

Cholesterol and triglyceride tests are blood tests that measure lipids—fats and fatty substances used as a source of energy by your body. Lipids are found in your blood and are stored in tissues. They are an important part of cells, and they help keep your body working normally. Lipids include cholesterol, triglycerides, high-density lipoprotein (HDL), and low-density lipoprotein (LDL).

Cholesterol and triglyceride tests measure:

Total cholesterol level.
Triglyceride level.
HDL cholesterol level. This is the "good" cholesterol.
LDL cholesterol level. This is the "bad" cholesterol.

Other measurements that may be done include:

Very-low-density lipoprotein (VLDL) cholesterol level.
The ratio of total cholesterol to HDL.
The ratio of LDL to HDL.

Your doctor may order these tests as part of a regular health exam. Your doctor may use the results to prevent, check on, or diagnose a medical condition. The results help your doctor check your risk of heart attack and stroke.

Follow your doctor's instructions on how to prepare for these tests. Your doctor may ask you to not eat or drink anything except water for 9 to 14 hours before your blood test. In most cases, you are allowed to take your medicines with water the morning of the test. Fasting is not always needed, but it may be recommended. Do not drink alcohol for 24 hours before the test.

Why It Is Done

Cholesterol and triglyceride testing is done:

As part of a routine physical examination to screen for high cholesterol and high triglycerides.
To check your response to medicine.
To help find your risk of having heart and blood flow problems, including heart attack and stroke.
If you have unusual symptoms, such as yellow fatty deposits in the skin (xanthomas). These symptoms may be caused by a genetic disease that causes very high cholesterol levels.

Cholesterol tests and heart attack risk

Your cholesterol levels can help your doctor find out your risk for having a heart attack or stroke.

But it's not just about your cholesterol. Your doctor uses your cholesterol levels plus other things to calculate your risk. These include:

Your blood pressure.
Whether or not you have diabetes.
Your age, sex, and race.
Whether or not you smoke.

Learn more

When to Have a Cholesterol Test

How To Prepare

Your doctor may ask you to not eat or drink anything except water for 9 to 14 hours before the tests. In most cases, you can take your medicines with water the morning of the test.
Do not drink alcohol for 24 hours before the tests.
Tell your doctor ALL the medicines and natural health products you take. Some may increase the risk of problems during your test. Your doctor will tell you if you should stop taking any of them before the test and how soon to do it.

How It Is Done

A health professional uses a needle to take a blood sample, usually from the arm.

Watch

Learning About Blood Tests for Children

How It Feels

When a blood sample is taken, you may feel nothing at all from the needle. Or you might feel a quick sting or pinch.

Risks

There is very little chance of having a problem from this test. When a blood sample is taken, a small bruise may form at the site.

Results

Results^{footnote 1,}^{footnote 2} are usually available within 24 hours.

If your LDL cholesterol is 4.5 mmol/L or more, it might mean that you have a familial lipid disorder.^{footnote 3}

Here are general facts about cholesterol and triglyceride levels (they may not all apply to you):

An HDL level of 1.5 mmol/L or higher is linked with a lower risk of heart disease.
An HDL cholesterol level less than 1.0 mmol/L raises your risk for developing heart disease, especially if you also have high total cholesterol levels.
The ratio of total cholesterol to "good" (HDL) cholesterol may be important, especially if total cholesterol is high.
Very high cholesterol and triglyceride levels may be caused by an inherited form of high cholesterol (hypercholesterolemia or hyperlipidemia).
Talk with your doctor about other things that raise your risk of heart problems. Your doctor may change your goals for cholesterol levels if you have other risk factors for coronary artery disease, such as:
- Smoking.
- High blood pressure.
- Diabetes.
- Family history of early CAD.
- You are a man and older than 40, or you are a woman and older than 50.
If you have a very high risk of having heart disease, your doctor may want your LDL level to be less than 2.0 mmol/L.

For children and teens, test results are slightly different than for adults.

Watch

Cholesterol Numbers: What They Mean for Your Health

Related Information

References

Citations
Grundy S, et al. (2002). Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) (NIH Publication No. 02–5215). Bethesda, MD: National Institutes of Health. Also available online: http://www.nhlbi.nih.gov/guidelines/cholesterol/atp3full.pdf.
Grundy SM, et al. (2004). Implications of recent clinical trials of the National Cholesterol Education Program Adult Treatment Panel III Guidelines. Circulation, 110(2): 227–239. [Erratum in Circulation, 110(6): 763.]
Brunham LR, et al. (2018). Canadian Cardiovascular Society position statement on familial hypercholesterolemia: Update 2018. Canadian Journal of Cardiology, 34(12): 1553–1563. DOI: 10.1016/j.cjca.2018.09.005. Accessed December 10, 2018.

Credits

Adaptation Date: 3/21/2022

Adapted By: Alberta Health Services

Adaptation Reviewed By: Alberta Health Services

Adapted with permission from copyrighted materials from Healthwise, Incorporated (Healthwise). This information does not replace the advice of a doctor. Healthwise disclaims any warranty and is not responsible or liable for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.