An aspartate aminotransferase (AST) test measures the amount of this enzyme in the blood. AST is normally found in red blood cells, liver, heart, muscle tissue, pancreas, and kidneys. AST formerly was called serum glutamic oxaloacetic transaminase (SGOT).
Low levels of AST are normally found in the blood. When body tissue or an organ such as the heart or liver is diseased or damaged, additional AST is released into the bloodstream. The amount of AST in the blood is directly related to the extent of the tissue damage. After severe damage, AST levels rise in 6 to 10 hours and remain high for about 4 days.
The AST test may be done at the same time as a test for alanine aminotransferase, or ALT. The ratio of AST to ALT sometimes can help determine whether the liver or another organ has been damaged. Both ALT and AST levels can test for liver damage.
An aspartate aminotransferase (AST) test is done to:
Tell your doctor if you:
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 may mean. To help you understand the importance of this test, fill out the medical test information form (What is a PDF document?).
The health professional taking a sample of your blood will:
The blood sample is taken from a vein in your arm. An elastic band is wrapped around your upper arm. It may feel tight. You may feel nothing at all from the needle, or you may feel a quick sting or pinch.
There is very little chance of a problem from having blood sample taken from a vein.
An aspartate aminotransferase (AST) test measures the amount of this enzyme in the blood. Results are usually available within 12 hours.
Normal values can vary widely from lab to lab.
10–36 U/L or 0.17–0.60 mckat/L
Very high levels of AST may be caused by:
Moderately high levels of AST may be caused by:
Slightly high levels of AST may be caused by:
AST levels may be high when a disease first develops, which is often when tissue damage is most severe. Decreasing levels of AST in the blood may be a sign of recovery from the disease or injury.
Reasons you may not be able to have the test or why the results may not be helpful include:
Other Works Consulted
- Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.
- Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
- Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby.
|Primary Medical Reviewer||Kathleen Romito, MD - Family Medicine|
|Primary Medical Reviewer||Donald Sproule, MD, CM, CCFP, FCFP - Family Medicine|
|Specialist Medical Reviewer||Peter J. Kahrilas, MD - Gastroenterology|
|Last Revised||February 8, 2010|
Last Revised: February 8, 2012
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