A patient asked that he was diagnosed with congenital hyperbilirubinemia many years ago, and he always thought that everything was normal except for high bilirubin, but during his physical examination last year, he found that γ-glutamyl transpeptidase 67.6 (normal 11~50), direct bilirubin 10.2 (0.1~5.0), total bilirubin 45.8 (3.4~17.1), and a few days ago, he found that γ-glutamyl transpeptidase 99.9. This makes the patient feel very anxious. What is the effect of persistently high γ-glutamyl transpeptidase on the liver? What kind of treatment is needed? Gamma glutamyl transpeptidase (GGT) is a common enzyme in the evaluation of liver function, and its distribution is wide, and it is also found in kidney, pancreas, heart and other tissues in addition to liver tissues. In liver tissues, GGT is mainly found in hepatocytes at the small bile ducts and is often associated with biliary stasis bile duct pathology, so we often call it “biliary tract enzyme”. Elevated levels of this enzyme are associated with many hepatobiliary diseases. Commonly, cholestatic diseases, such as primary biliary cirrhosis, autoimmune hepatitis, intrahepatic cholestasis caused by drugs or viruses, biliary obstruction caused by stones or tumors, etc.; also seen in acute and chronic liver damage, such as fatty liver, alcoholic liver, chronic viral hepatitis, etc. In addition, the enzyme is associated with liver fibrosis and is often elevated in patients with liver cirrhosis. Due to its wide distribution, elevated GGT can also be seen in non-liver diseases such as diabetes, kidney damage and myocarditis. Therefore, it is recommended that the patient go to the hospital for imaging tests such as ultrasound or CT or MR, liver and kidney function, blood lipid and blood glucose, and hepatitis B and C virus markers. Your current GGT is only mildly to moderately elevated, probably mostly due to inflammatory liver damage (fatty liver, alcoholic liver, etc.), so there is no need to be overly anxious. After the condition is clear, appropriate treatment is sufficient.