GGT (Gamma-Glutamyl Transferase) is a blood test that measures ggt (gamma-glutamyl transferase) levels in the blood. Normal range: GGT is typically below about 60 U/L (men tend to run a little higher than women, and ranges vary by lab). It is a sensitive but non-specific liver marker, so its main value is in combination with ALP and the rest of the liver panel rather than alone.. It is commonly used to a sensitive indicator of liver disease, alcohol consumption, and certain medications..
What is GGT (Gamma-Glutamyl Transferase)?
An enzyme found in many tissues, especially the liver.
Why is it measured?
A sensitive indicator of liver disease, alcohol consumption, and certain medications.
Normal Reference Range
GGT is typically below about 60 U/L (men tend to run a little higher than women, and ranges vary by lab). It is a sensitive but non-specific liver marker, so its main value is in combination with ALP and the rest of the liver panel rather than alone.
Note: Reference ranges may vary between laboratories. Always consult your healthcare provider for interpretation.
What Causes High GGT?
GGT is one of the most sensitive liver enzymes and rises with a wide range of insults: regular or heavy alcohol intake, non-alcoholic fatty liver disease (very common with overweight and metabolic syndrome), blocked bile flow, and many medications, including some that simply induce the enzyme without causing damage. Its key diagnostic role is confirming that a raised ALP comes from the liver (GGT also high) rather than from bone (GGT normal).
What Causes Low GGT?
A low GGT has no clinical significance. A normal GGT is useful information — it suggests a raised ALP is from bone rather than the liver.
How Often Should GGT Be Tested?
GGT is part of routine liver function tests. It is particularly used to investigate a raised ALP, to assess possible alcohol-related or fatty liver disease, and to monitor known liver conditions. There is no need to test it in isolation.
Related Blood Markers
GGT is interpreted with ALP (to localise to the liver), and with ALT, AST and bilirubin in the full liver panel. In fatty liver, it is considered alongside the lipid panel, glucose and HbA1c.
Key Facts
- •Category: Vital Organ Functions
- •Unit of Measurement: U/L
- •Test Code: GGT
Related Vital Organ Functions Markers
Albumin
The main protein in blood plasma, produced by the liver.
Learn moreALP (Alkaline Phosphatase)
An enzyme found primarily in the liver and bones.
Learn moreALT (Alanine Transaminase)
ALT (Alanine Transaminase, also written ALAT or SGPT) is an enzyme concentrated in the liver. When liver cells are damaged, ALT leaks into the bloodstream, so it is the single most liver-specific enzyme on a standard Liver Function Test (LFT). It is often interpreted alongside AST, GGT and ALP to build a picture of liver health.
Learn moreAST (Aspartate Transaminase)
AST (Aspartate Transaminase, also written ASAT or SGOT) is an enzyme found in the liver, heart, skeletal muscle and red blood cells. Because AST exists in multiple tissues, it is less liver-specific than ALT. Pathology labs report AST as part of the standard Liver Function Test (LFT) panel.
Learn moreBilirubin
A yellow pigment produced during the breakdown of red blood cells.
Learn moreBUN (Blood Urea Nitrogen)
A waste product filtered by the kidneys.
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