Can this result diagnose a condition on its own?

No. Laboratory results are interpreted with symptoms, medical history, specimen conditions and related tests.

Which reference range should I use?

Start with the performing laboratory's own reference interval; clinical cutoffs, when relevant, are separate sourced thresholds used for a specific purpose.

When should I discuss the result with a healthcare professional?

Results that are clearly outside range, persistent, symptomatic or unexpected should be reviewed by a healthcare professional.

Information about a laboratory test

High GGT: What Does It Mean?

High GGT can occur with liver or bile-duct involvement; alcohol and some medicines can also affect the level.

Test summary

Test name: GGT
Abbreviations: GGT, Gamma-GT, GGTP
Category: Hepatology / Cholestatic Enzymes
Panel: Liver Function Panel
Specimen: Serum / plasma
Common units: U/L, µkat/L

What does the test measure?

Measures gamma-glutamyl transferase activity in blood, most clinically relevant to liver and bile-duct assessment.

Why is the test ordered?

Often used with ALP and other liver tests to help determine whether an abnormal pattern is more consistent with hepatobiliary involvement.

Information about a low result

Low GGT is generally not a problem on its own.

Information about a high result

High GGT can occur with liver or bile-duct involvement; alcohol and some medicines can also affect the level.

Reference and clinical context

Start with the performing laboratory's reference interval, unit and specimen conditions. Numeric information on this page is stored as sourced example intervals or clinical thresholds.

Reference ranges may vary by laboratory, method used, age, sex, pregnancy status, and clinical context. The reference range on your own laboratory report takes precedence.

Interpretation notes

GGT does not identify a cause by itself. Interpretation with ALP, ALT, AST and bilirubin is more informative.

Related specialties

Gastroenterology
Internal Medicine
Family Medicine

Frequently asked questions

Sources

Liver Function Tests — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2026 · Liver panel components, purposes, pattern-based interpretation and limitations · Verified: Aug 12, 2026
Gamma-glutamyl Transferase (GGT) Test — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2026 · GGT purpose and interpretation with ALP and other liver tests · Verified: Aug 12, 2026
ALP - Blood Test — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2026 · ALP tissue sources, adult example interval and bone/liver interpretation · Verified: Aug 12, 2026