What is it?
Gamma-glutamyl transferase (GGT) is an enzyme found mainly in the liver. When the liver function is impared or the path of bile flow is obstructed or restricted, the concentration of GGT in your blood may rise.
It is a good biomarker for detecting bile duct problems or general monitoring as part of a liver investigation.
Reference ranges
If your indicative GGT level is lower than the reference range for our laboratory:
Generally, there are no health conditions that cause low GGT levels, so it will imply that you do not have a liver issue. In women, oral contraceptives and clofibrate can reduce GGT levels.
Please discuss this result with your GP if you are concerned.
If your indicative GGT level is higher than the reference range for our laboratory:
Usually this will indicate an issue with the liver. In general, concentrations of GGT are proportional to the liver damage. However, higher GGT may also be due to heart issues or alcohol abuse, use of many prescription and non-prescription drugs including Non-Steroidal Anti-Inflammatory Drugs (NSAID) or antibiotics, use of hormones and HRT and so on.
Please discuss this result with your GP.
