Health
Fact-checked

At WiseGEEK, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What is an AST Test?

Nat Robinson
Nat Robinson

An AST test is a medical test used to find an enzyme known as aspartate aminotransferase (AST) in red blood cells. Generally, most individuals have small amounts of AST in the body; however, it is produced in high quantities in organs such as the liver and heart when there is damage or disease present. Also used to detect blood enzymes called serum glutamic oxaloacetic transaminase, the AST test may alternatively be known as a SGOT test. Although it can indicate damage to more than one organ in the human body, it is primarily used in individuals suspected to have liver disease.

There are certain factors that may lead a doctor to order an AST test for a patient. Individuals with recent exposure to a person with hepatitis, an inflammation of the liver, may fit within this criteria. An alcoholic may receive an AST test if he or she is suspected to have liver damage, such as cirrhosis. Additionally, liver disease may be genetic and run in families. General symptoms of a liver disorder can include dark urine, abdominal swelling and pain, nausea, vomiting, and yellowing of the skin and eyes, which is a condition known as jaundice.

Some types of liver disease may be diagnosed, in part, with an AST test.
Some types of liver disease may be diagnosed, in part, with an AST test.

The doctor will generally inform the patient if any particular type of preparation will be needed prior to having the test. Exercise should be excluded on the day of the test, as it may raise AST levels. Medications that may alter the results may need to be avoided or taken at a later time. This may include herbal medications. It will also be necessary to inform the doctor if the patient has any condition that may interfere with the blood work; pregnancy, for example, may cause lower AST levels.

An AST test requires a blood sample.
An AST test requires a blood sample.

As an AST test is performed with a simple blood test, it has few complications. Some people may experience mild bruising where the needle was inserted. In some cases, a small clot or hematoma may appear at the needle's injection site. In rare instances, more severe complications may arise, such as fainting, an infection, or severe bleeding.

The doctor will be able to provide the patient with the results of the AST test usually within a few days. Normal results will mean there is no significant damage to the organs. Abnormal results may signify the presence of a disease and will need further investigation to ensure proper treatment. Patients should consult with the doctor ordering the test to address questions and concerns in advance.

Discussion Comments

burcidi

@turquoise-- I agree with you but an AST test is not enough to determine organ damage or disease. Like the article said, various factors can affect results of the test.

Aside from this though, when organ damage has reached a certain extent, the AST test might not give very accurate results.

A friend of mine had liver failure and then a liver transplant. Right before the transplant, the AST gave low test results despite the organ being completely diseased. Since no more damage was actually possible to the organ, AST amounts in the blood was coming back normal.

So a doctor diagnosis is always necessary in addition to the AST.

turquoise

@fify-- Absolutely, the AST/SGOT test can be used not only to detect disease in organs, but also to detect how much damage has been done or is being done on the organs at present. These tests show how much scar tissue is present in organs like the kidney and the more the scar tissue, the more damage there is.

In addition, the amount of AST in blood should normally be around 50, so any result above this also means damage to the organs.

I personally think that people who heavily use alcohol should have this test done to know about their liver health. There is always something to be done and precautions that can be taken, so AST is important.

fify

Is an AST test useful before disease happens?

For example, can someone who drinks a lot go and get the test done to determine if and how much damage he or she is causing to the kidney?

I guess what I'm wondering is if blood work and AST test could be used as a warning to help people take certain precautions for disease. Can an alcoholic be urged to stop drinking, or someone with genetic kidney disease be urged to change their lifestyle or eating habits with the help of this test? Or does it diagnose disease only after it has occurred?

Post your comments
Login:
Forgot password?
Register:
    • Some types of liver disease may be diagnosed, in part, with an AST test.
      By: peterjunaidy
      Some types of liver disease may be diagnosed, in part, with an AST test.
    • An AST test requires a blood sample.
      By: Wojciech Sobiech
      An AST test requires a blood sample.
    • An AST test is used to find a particular enzyme in red blood cells.
      By: Monika 3 Steps Ahead
      An AST test is used to find a particular enzyme in red blood cells.
    • A doctor can offer consultation on the results of an AST test.
      By: Shakzu
      A doctor can offer consultation on the results of an AST test.