Biochemistry Test

Test : Alanine transaminase

Indications : The alanine aminotransferase (ALT) test is done for the following reasons-

• Diagnose liver diseases, such as cirrhosis and hepatitis
• Diagnose liver damage due to other causes
• Find out if jaundice caused in a person is a result of liver disease or blood –related disorders

Prior to taking the test, talk to the doctors regarding the medicines and herbal supplements that you may be taking. Some of these need to be stopped, as it interferes with the test results. Also, avoid doing strenuous exercise prior to the test. Cardiac catheterization, few days before the test, can also interfere with the results.

The blood sample for the test is usually taken intravenously and normally involves very little risk.


Physiology : Alanine aminotransferase (ALT) is an enzyme mostly found in the liver. It is also found in smaller measures in the kidneys, heart, muscles and the pancreas. ALT was earlier referred to as serum glutamic pyruvic transaminase (SGPT).

ALT is measured if liver damage is suspected. Normally low levels of ALT are found in the blood. But when liver damage sets in, ALT is released into the bloodstream, raising their levels.

The ALT test is often done along with other tests such as aspartate aminotransferase (AST), alkaline phosphatase, bilirubin and lactate dehydrogenase (LDH). Both ALT and AST levels are taken into consideration as reliable tests to diagnose liver damage. The ALT /AST ratio is taken, particularly, to diagnose liver damage caused by alcoholism.

Normal Range : 0-35U/L

Interpretation : The results of the ALT test is usually available within 12 hours. The normal values-

• 10-40 units /liter (U /L) for males
• 7 -35 units /liter (U/L) for females

High ALT values indicate-

• Liver damage due to hepatitis /cirrhosis
• Exposure to carbon tetrachloride
• Lead poisoning
• Necrosis
• Intake of certain medications
• Growth spurts in the young

More Information

In children with acute lymphocytic leukemia (ALL), high ALT values could indicate bad prognosis.

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