Skip navigation
MedlinePlus Trusted Health Information for You U.S. National Library of MedicineNational Institutes of Health
Contact Us FAQs Site Map About MedlinePlus
español Home Health Topics Drug Information Medical Encyclopedia Dictionary News Directories Other Resources

 

Medical Encyclopedia

Other encyclopedia topics:  A-Ag  Ah-Ap  Aq-Az  B-Bk  Bl-Bz  C-Cg  Ch-Co  Cp-Cz  D-Di  Dj-Dz  E-Ep  Eq-Ez  F  G  H-Hf  Hg-Hz  I-In  Io-Iz  J  K  L-Ln  Lo-Lz  M-Mf  Mg-Mz  N  O  P-Pl  Pm-Pz  Q  R  S-Sh  Si-Sp  Sq-Sz  T-Tn  To-Tz  U  V  W  X  Y  Z  0-9 

Triglyceride level

Printer-friendly versionEmail this page to a friend
Contents of this page:

Illustrations

Blood test
Blood test

Alternative names    Return to top

TG; Triacylglycerol

Definition    Return to top

This test that measures the amount of triglyceride in the blood.

How the test is performed    Return to top

Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and a tourniquet (an elastic band) or blood pressure cuff is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the tourniquet to distend (fill with blood).

A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the tourniquet is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

Infant or young child:
The area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.

How to prepare for the test    Return to top

Fast for 8 to 12 hours before the test. The health care provider may advise you to withhold drugs that may affect the test (see special considerations).

Infants and children:
The preparation you can provide for this test depends on your child's age, previous experiences, and level of trust. For general information regarding how you can prepare your child, see the following:

How the test will feel    Return to top

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    Return to top

Triglycerides are often measured as a reflection of fat (lipid) ingestion and metabolism, or as part of an evaluation of coronary risk factors.

Triglycerides comprise the largest proportion of fats (lipids) in the diet, in the adipose tissue, and in the blood. Immediately after a meal, triglycerides appear in the blood as the major constituent of chylomicrons.

Under normal circumstances, triglycerides within chylomicrons are stripped of fatty acids as they pass through various tissues (especially adipose and skeletal muscle). The chylomicron remnant is then taken up by the liver so that chylomicrons disappear from the blood within 2 or 3 hours.

The remaining triglycerides, plus additional triglycerides synthesized within the liver, are then re-packaged as VLDL and secreted into the blood from the liver.

Triglycerides are a storage form of energy. They are stored in adipose tissue and muscle, and gradually released and metabolized between meals according to the energy needs of the body.

Normal Values    Return to top

What abnormal results mean    Return to top

High triglyceride levels may be associated with a higher risk for heart disease and stroke. This is especially true because people with high triglycerides often have other conditions, such as diabetes and obesity, that increase the likelihood of developing cardiovascular disease.

High triglyceride levels may indicate:

Low levels may indicate: Additional conditions under which the test may be performed:

What the risks are    Return to top

Special considerations    Return to top

Pregnancy can interfere with test results.

Drugs that can increase triglyceride measurements include cholestyramine, estrogens, and oral contraceptives.

Drugs that can decrease triglyceride measurements include ascorbic acid, asparaginase, clofibrate, and colestipol.

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.

Update Date: 9/2/2003

Updated by: A.D.A.M. editorial. Previously reviewed by Jeffrey Heit, M.D., Department of Medicine, University of Pennsylvania Health System, Philadelphia, PA. Review provided by VeriMed Healthcare Network (10/27/01).

adam.com logo

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2002 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.