Biochemistry Test

Test : Aspartate transaminase

Indications : An AST test is ordered for the following reasons -

• When a person shows symptoms of liver disease - fatigue, weakness, nausea, vomiting, abdominal pain or swelling, jaundice, dark urine, light colored stool, itching

• To monitor those who are heavy drinkers, those who have been exposed to hepatitis virus, those who have had liver disease in the family, those who are diabetic or obese

• To monitor liver function in those who are taking certain medications. If ALT is high they may have to change the medications to reduce toxicity

• To monitor effect of treatment in those with liver disease

Fasting blood samples may be taken from the forearm to carry out the test.


Physiology : The blood test for aspartate transaminase (AST) is usually carried out to detect liver damage. The test is always done in combination with the test for another liver enzyme, alanine amino transferase (ALT), to help diagnose liver problems.

However, ALT is the more specific of the two. Sometimes a ratio of the two enzymes is derived to come to a conclusion.

AST levels are also often measured and compared with measures of alkaline phosphatase, bilirubin and total protein to understand the nature of liver disease.

Normal Range : 17-59U/L

Interpretation : Normally, levels of AST in the blood are low. It ranges from 17-59 U/L. But these values vary from lab to lab.

Higher than normal values indicates -

• Acute viral hepatitis (10 times greater than normal value)
• Chronic hepatitis (less than 4 times higher than normal value)
• Cirrhosis
• Post heart attack

More Information

AST /ALT ratio is also increased after alcoholic hepatitis.

Pregnancy, certain medications, conditions of the heart or muscles and pancreatitis can also raise AST levels.

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