The triglyceride level is a laboratory test to measure the amount of triglycerides in your blood. Triglycerides are a type of fat.
Your body makes some triglycerides. Triglycerides also come from the food you eat. When you eat, your body uses carbohydrate calories for immediate energy. Leftover calories are turned into triglycerides and stored in fat cells for later use. If you eat more calories than your body needs, your triglyceride level may be high.
How the test is performed
Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.
Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.
Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.
In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.
How to prepare for the test
You should not eat for 8 to 12 hours before the test.
Alcohol and certain drugs may affect test results. Make sure your doctor knows what medicines you take, including over-the-counter drugs and supplements. Your doctor may tell you to temporarily stop taking certain medicines. Never stop taking any medicine without first talking to your doctor.
Drugs that can increase triglyceride measurements include beta blockers, cholestyramine, colestipol, estrogens, protease inhibitors, retinoids, certain antipsychotics, and birth control pills.
Drugs that can decrease triglyceride measurements include ascorbic acid, asparaginase, clofibrate, fenofibrate, fish oil, gemfibrozil, nicotinic acid, and statin medications.
How the test will feel
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the test is performed
The most important use of this test is to help estimate your LDL cholesterol. This test is also done to help determine your risk of developing heart disease. A high triglyceride level may lead to atherosclerosis, which increases your risk of heart attack and stroke. A high triglyceride level may also cause inflammation of your pancreas.
Persons with a high triglyceride level often have other conditions such as diabetes and obesity that also increase the chances of developing heart disease.
The triglyceride level is usually included in a lipid panel or coronary risk profile.
- Normal: Less than 150 mg/dL
- Borderline High: 150 - 199 mg/dL
- High: 200 - 499 mg/dL
- Very High: 500 mg/dL or above
What abnormal results mean
High triglyceride levels may be due to:
- Diet low in protein and high in carbohydrates
- Familial hyperlipoproteinemia (rare)
- Nephrotic syndrome
- Poorly controlled diabetes
Low triglyceride levels may be due to:
Additional conditions under which the test may be performed:
What the risks are
Veins and arteries vary in size from one patient to another, and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others. Other risks may include:
- Excessive bleeding
- Fainting or feeling light-headed
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Pregnancy can interfere with test results.
Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. Executive summary of the 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). JAMA. 2001;285(19):2486-2497.
Implications of recent clinical trials for the National Cholesterol Education Program Adult Treatment Panel III guidelines. Circulation. 2004 Jul 13; 110(2):227-39.
Semenkovich CF. Disorders of lipid metabolism. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 217.
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.