There are physiologic causes, liver lesions and extrahepatic lesions for high ALT. The high level of AAT indicates that the liver cells are damaged, and further aggravation of the condition may result in weakness, nausea, ascites, vomiting of blood and other symptoms. 1. Physiological reasons: long-term alcoholism, late night, tiredness and consumption of stimulating foods such as spicy hot pot, fried chicken, beer, etc., can cause a temporary increase in ALT, which can be normalized after rest, reasonable diet, etc., and will not cause great harm to the liver. 2. Liver lesions: Chlorpromazine, isoniazid, acetylsalicylic acid, ampicillin, carbon tetrachloride, organophosphorus and other drugs that have damage to the liver can cause drug hepatitis, viral hepatitis caused by viral infections, alcoholic cirrhosis and fatty liver disease caused by alcohol consumption can cause elevated ALTD and damage to the liver cells, and even cause liver fibrosis, cancer and other hazards. 3. Extra-hepatic lesions: cholangitis, myocardial injury, renal infarction and other diseases can also cause elevated aminotransferase. For patients with elevated AST, it is recommended to consult a doctor in time for a clear diagnosis and targeted treatment under the doctor’s guidance.