URL of this page: https://medlineplus.gov/lab-tests/liver-function-tests/

Liver Function Tests

What are liver function tests?

Liver function tests (also known as a liver panel) are blood tests that measure different enzymes, proteins, and other substances made by the liver. These tests check the overall health of your liver. The different substances are often tested at the same time on a single blood sample, and may include the following:

  • Albumin, a protein made in the liver
  • Total protein. This test measures the total amount of protein in the blood.
  • ALP (alkaline phosphatase), ALT (alanine transaminase), AST (aspartate aminotransferase), and gamma-glutamyl transpeptidase (GGT). These are different enzymes made by the liver.
  • Bilirubin, a waste product made by the liver.
  • Lactate dehydrogenase (LD), an enzyme found in most of the body's cells. LD is released into the blood when cells have been damaged by disease or injury.
  • Prothrombin time (PT), a protein involved in blood clotting.

If levels of one or more of these substances are outside of the normal range, it may be a sign of liver disease.

Other names: liver panel, liver function panel, liver profile hepatic function panel, LFT

What are they used for?

Liver function tests are most often used to:

  • Help diagnose liver diseases, such as hepatitis
  • Monitor treatment of liver disease. These tests can show how well the treatment is working.
  • Check how badly a liver has been damaged or scarred by disease, such as cirrhosis
  • Monitor side effects of certain medicines

Why do I need liver function testing?

You may need liver function testing if you have symptoms of liver disease. These include:

You may also need these tests if you have certain risk factors. You may be at higher risk for liver disease if you:

  • Have a family history of liver disease
  • Have alcohol use disorder, a condition in which you have difficulty controlling how much you drink
  • Think you have been exposed to a hepatitis virus
  • Take medicines that may cause liver damage

What happens during a liver function test?

A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

Will I need to do anything to prepare for the test?

You may need to fast (not eat or drink) for 10-12 hours before the test.

Are there any risks to the test?

There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

What do the results mean?

If one or more of your liver function test results were not normal, it may mean your liver is damaged or not working properly. Liver damage can be caused by a number of different conditions, including:

If you have questions about your results, talk to your health care provider.

Is there anything else I need to know about liver function tests?

If any of your liver function tests were not normal, your provider may need more tests to confirm or rule out a specific diagnosis. These tests may include more blood tests and/or a liver biopsy. A biopsy is a procedure that removes a small sample of tissue for testing.

References

  1. Cleveland Clinic [Internet]. Cleveland (OH): Cleveland Clinic; c2019. Liver Function Tests: Overview [cited 2019 Aug 26]; [about 3 screens]. Available from: https://my.clevelandclinic.org/health/diagnostics/17662-liver-function-tests
  2. Cleveland Clinic [Internet]. Cleveland (OH): Cleveland Clinic; c2019. Liver Function Tests: Test Details [cited 2019 Aug 26]; [about 3 screens]. Available from: https://my.clevelandclinic.org/health/diagnostics/17662-liver-function-tests/test-details
  3. Kids Health from Nemours [Internet]. Jacksonville (FL): The Nemours Foundation; c1995–2019. Blood Test: Liver Function Tests [cited 2019 Aug 26]; [about 3 screens]. Available from: https://kidshealth.org/en/teens/test-liver-function.html
  4. Lab Tests Online [Internet]. Washington D.C.; American Association for Clinical Chemistry; c2001–2019. Biopsy [updated 2017 Jul 10; cited 2019 Aug 26]; [about 2 screens]. Available from: https://labtestsonline.org/glossary/biopsy
  5. Lab Tests Online [Internet]. Washington D.C.; American Association for Clinical Chemistry; c2001–2019. Lactate Dehydrogenase (LD) [updated 2018 Dec 20; cited 2019 Aug 26]; [about 2 screens]. Available from: https://labtestsonline.org/tests/lactate-dehydrogenase-ld
  6. Lab Tests Online [Internet]. Washington D.C.; American Association for Clinical Chemistry; c2001–2019. Liver Panel [updated 2019 May 9; cited 2019 Aug 26]; [about 2 screens]. Available from: https://labtestsonline.org/tests/liver-panel
  7. Mayo Clinic [Internet]. Mayo Foundation for Medical Education and Research; c1998–2019. Liver Function Tests: About; 2019 Jun 13 [cited 2019 Aug 26]; [about 3 screens]. Available from: https://www.mayoclinic.org/tests-procedures/liver-function-tests/about/pac-20394595
  8. Merck Manual Consumer Version [Internet]. Kenilworth (NJ): Merck & Co., Inc.; c2019. Liver Function Tests [updated 2017 May; cited 2019 Aug 26]; [about 2 screens]. Available from: https://www.merckmanuals.com/home/liver-and-gallbladder-disorders/diagnosis-of-liver,-gallbladder,-and-biliary-disorders/liver-function-tests?query=liver%20panel
  9. National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Blood Tests [cited 2019 Aug 26]; [about 3 screens]. Available from: https://www.nhlbi.nih.gov/health-topics/blood-tests
  10. UF Health: University of Florida Health [Internet]. Gainesville (FL): University of Florida Health; c2019. Liver function tests: Overview [updated 2019 Aug 25; cited 2019 Aug 26]; [about 2 screens]. Available from: https://ufhealth.org/liver-function-tests
  11. University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2019. Health Encyclopedia: Liver Panel [cited 2019 Aug 26]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=167&ContentID=liver_panel
  12. UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2019. Health Information: Liver Function Panel: Topic Overview [updated 2018 Jun 25; cited 2019 Aug 26]; [about 2 screens]. Available from: https://www.uwhealth.org/health/topic/special/liver-function-panel/tr6148.html
  13. UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2019. Health Information: Liver Function Tests: Exam Overview [updated 2018 Jun 25; cited 2019 Aug 26]; [about 2 screens]. Available from: https://www.uwhealth.org/health/topic/testdetail/liver-function-tests/hw144350.html#hw144367

The medical information provided is for informational purposes only, and is not to be used as a substitute for professional medical advice, diagnosis or treatment. Please contact your health care provider with questions you may have regarding medical conditions or the interpretation of test results.

In the event of a medical emergency, call 911 immediately.