GGT

Ordering the GGT with Access Medical Laboratories

A GGT (gamma-glutamyl transferase) test measures the levels of GGT in the blood.

GGT is an enzyme mainly found in the liver but also throughout the body. When the liver is damaged, GGT levels can go to the bloodstream. Thus, high levels of GGT in the blood may be a sign of liver damage or disease. The GGT levels can also increase due to medications or alcohol.

GGT is typically the first liver enzyme to increase in the blood when the liver bile ducts become blocked or constricted. GGT is the most sensitive liver enzyme test for finding bile duct issues.

A GGT test alone can't diagnose the specific cause of liver disease. It is usually requested with or after other liver function tests, such as the alkaline phosphatase (ALP) blood test.

When is the GGT Commonly Ordered?

A doctor may order a GGT test for the following reasons:

• Part of regular blood testing or physical examination.
• If a person is taking a medication that has potentially toxic effects on the liver.
• To help diagnose liver disease.
• To determine if the liver damage is due to liver disease or a bone disorder. To check for blockages in the bile ducts.
• To screen for or monitor alcohol use disorder.