A GGT (Gamma-Glutamyl Transferase) test measures the level of the GGT enzyme in the blood. GGT is an enzyme found mainly in the liver, but also in the kidneys, pancreas, and intestines. It plays a role in the metabolism of glutathione and the transport of amino acids and peptides across cell membranes.
This test is primarily used to detect liver disease and bile duct disorders. GGT is one of the most sensitive markers of liver damage and is particularly elevated in cases of alcohol-related liver disease, making it useful in assessing alcohol consumption. It is often ordered alongside ALP (Alkaline Phosphatase) — if both are elevated, it points more specifically to liver or bile duct disease rather than bone disease. It also helps monitor patients with known liver conditions or those taking medications that may affect the liver.
