Serum gamma-glutamyltransferase, which has a normal value of 20-40 U/L, was checked at 139.2 U/L, which is above the normal range. So it is on the high side. Elevated serum gamma-glutamyltransferase may be caused by impaired liver function, which is common in people who drink a lot of alcohol, often stay up late, take drugs that damage liver cells, viral hepatitis, fatty liver disease, autoimmune liver disease, and biliary tract obstructive disease. In case of elevated serum gamma-glutamyltransferase, it is recommended to improve liver function, liver and gallbladder ultrasound, hepatitis B five tests, etc., to clarify the specific causes of the disease, and then carry out treatment for the causes under the guidance of the doctor.