Synonyms: ALT; Glutamic Pyruvate Transaminase; GPT; SGPT; Transaminases

NOTICE: This test is a component of the Comprehensive Metabolic panel which may be more appealing than ordering this test alone.

Why It Is Done

Identify liver disease, especially cirrhosis and hepatitis caused by alcohol, drugs, or viruses. Help check for liver damage. Find out whether jaundice was caused by a blood disorder or liver disease. Keep track of the effects of cholesterol-lowering and other medications that can damage the liver.

Test Overview

An alanine aminotransferase (ALT) test measures the amount of this enzyme in the blood. ALT is found mainly in the liver, but also in smaller amounts in the kidneys, heart, muscles, and pancreas.

ALT is measured to see if the liver is damaged or diseased. Low levels of ALT are normally found in the blood. However, when the liver is damaged or diseased, it releases ALT into the bloodstream, which makes ALT levels go up. Most increases in ALT levels are caused by liver damage.

The ALT test is often done along with other tests that check for liver damage, including aspartate aminotransferase (AST), alkaline phosphatase, lactate dehydrogenase (LDH), and bilirubin. Both ALT and AST levels are reliable tests for liver damage.

How To Prepare

Avoid strenuous exercise just before having an ALT test.