AST Test (Aspartate Aminotransferase)
Reviewed
Also called: SGOT test, serum glutamic oxaloacetic transaminase test, aspartate transaminase test
An AST blood test measures the amount of AST in your blood. This test is commonly used to help diagnose liver damage or disease.
Specimen: blood
Why this test may be ordered
- As part of a routine blood screening to check the health of your liver
- To help diagnose or monitor liver problems
- To help diagnose other health conditions
- If you have symptoms of liver damage (nausea, vomiting, lack of appetite, fatigue, weakness, jaundice, abdominal swelling/pain, ankle/leg swelling, dark urine, light-colored stool, frequent itching)
- If you are at higher risk for liver disease due to family history, alcohol use disorder, obesity, diabetes, certain medicines, hepatitis, or exposure to hepatitis
Preparation and collection
You may need to stop taking certain medicines before the test, so tell your provider about everything you take. But don't stop taking any medicines unless your provider tells you to.
A health care professional will take a blood sample from a vein in your arm, using a small needle. This usually takes less than five minutes.
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.
Understanding results
Low levels of AST in the blood are usually considered normal. High levels of AST in the blood may be due to liver disease or other liver problems.
- High AST level: High levels of AST in the blood may be due to liver disease or other liver problems. Other reasons you may have high levels of AST can include: hepatitis, cirrhosis, mononucleosis, heart procedures or problems, pancreatitis. Limitation: If your results are not in the normal range, it doesn't always mean that you have a medical condition that needs treatment. Many things can affect your results, such as pregnancy, exercise, certain medicines, and your age or sex. Next step: Talk with your provider to learn what your results mean.
- Low AST level: Low levels of AST in the blood are usually considered normal. Limitation: If you have high levels of AST and/or ALT, it may mean that you have some type of liver damage. Next step: Your health care provider may order an ALT blood test along with your AST blood test.
- Many things can affect your results, such as pregnancy, exercise, certain medicines, and your age or sex.
- A result that is not in the normal range does not always mean that you have a medical condition that needs treatment.
- The test is not diagnostic by itself; it is often part of a group of liver function tests.
What to do next
Talk with your provider to learn what your results mean.
- What do my AST results mean in my specific situation?
- Do I need any follow-up tests, such as an ALT test or other liver function tests?
- Should I make any changes to my medicines or lifestyle based on these results?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.
U.S. National Library of Medicine: AST Test (Aspartate Aminotransferase)