Gamma-glutamyl Transferase (GGT) Test Test
A GGT test measures the level of gamma-glutamyl transferase in your blood. High levels may indicate liver damage or bile duct problems.
What this test measures
The GGT test measures the amount of gamma-glutamyl transferase (GGT) in your blood. GGT is an enzyme mainly found in the liver. When the liver or bile ducts are damaged, GGT can leak into the bloodstream.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Higher-than-normal results
Higher-than-normal GGT levels may be a sign of liver damage. Possible causes include hepatitis, cirrhosis, alcohol use disorder, pancreatitis, diabetes, heart failure, or side effects of certain medicines. The higher the level, the more liver damage there may be.
Lower-than-normal results
Low or normal GGT levels usually mean you probably don't have liver disease.
Frequently asked questions
What is a GGT test?
A GGT test measures the amount of gamma-glutamyl transferase in your blood. It helps check for liver damage or bile duct problems.
Why might I need a GGT test?
You may need it to help diagnose liver disease, check for bile duct blockages, or screen for alcohol use disorder.
What does a high GGT level mean?
A high GGT level may mean liver damage. It could be due to hepatitis, cirrhosis, alcohol use, pancreatitis, diabetes, heart failure, or medicine side effects.
What does a low GGT level mean?
Low or normal GGT levels usually mean you probably don't have liver disease.
How is GGT test used with ALP test?
If both ALP and GGT are high, it likely points to a liver disorder. If ALP is high but GGT is low or normal, it suggests a bone disorder.
Related lab tests
Sources
- MedlinePlus: Gamma-glutamyl Transferase (GGT) Test — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.