The normal range is 0-40 U/L. According to the degree of aminotransferase elevation, it can be clinically classified into mild, moderate and severe elevation. Transaminase 800U/L is most likely to be severely elevated. The common causes of elevated transaminase are acute viral hepatitis, acute attack of chronic viral hepatitis, and drug-related liver injury. Acute viral hepatitis can be cured clinically through standardized liver protection and symptomatic treatment, which will not affect survival; acute attack of chronic hepatitis B can be cured clinically through standardized liver protection, enzyme reduction and antiviral treatment, which will not affect survival; drug-related liver damage can be restored to normal liver function through treatment, which will not affect survival.