The normal range of AST is 0~40 U/L. AST 55 U/L is a mild elevation, which may be related to physiological factors, hepatitis, intrahepatic cholestasis and other reasons. 1. Physiological factors: strenuous exercise, staying up late, drinking alcohol before the test can cause a mild increase in AST, which can be changed to the normal range by changing lifestyle habits and reviewing AST again. 2. Hepatitis: AST mainly exists in liver cells, because of virus or drug damage to liver cells, resulting in destruction of liver cells, AST will be released into the bloodstream, causing AST elevation. 3. Biliary stasis in the liver: long-term retention of bile salts and other substances in the bile in the liver will cause damage to liver cells, liver cell membrane damage increased permeability, glutamine transaminase is released into the blood plasma, resulting in elevated blood glutamine transaminase test value. Patients with 55 U/L of glutamic oxal transaminase should go to the hospital in time to improve the examination, to clarify the cause of the elevated glutamic transaminase, and early treatment.