The normal range of alanine aminotransferase is 5～40U/L, so alanine aminotransferase is high when it is 77U/L. It is considered to be caused by physiological and medication factors, or it may be caused by cirrhosis of the liver, fatty liver, cholelithiasis, myocarditis and other disease factors. 1. Physiological and drug factors: staying up late, strenuous exercise, excessive fatigue and other factors can also cause ALT elevation; taking methimazole, isoniazid and other drugs may also cause ALT elevation. 2. Disease factors: fatty liver, autoimmune liver disease, cirrhosis and other liver diseases can have alanine aminotransferase elevation; acute cholangitis, bile duct hemorrhage, cholelithiasis can also cause alanine aminotransferase elevation, but also accompanied by bilirubin elevation; myocarditis, acute cardiac infarction can cause alanine aminotransferase elevation, may be accompanied by glutamic oxalate aminotransferase elevation. It is recommended to go to the hospital after eliminating physiological factors in the presence of ALT elevation.