A high level of ALT is generally indicative of liver damage, which is commonly caused by viral infections, drugs, alcohol and other causes of hepatitis, and may also be physiological elevation caused by staying up all night, exertion, and other causes. 1. Viral infection: the most common factor, such as hepatitis virus and other liver cell damage caused by the hepatitis virus, will cause the level of ALT to increase, sometimes other indicators are normal. 2. Drugs: Some drugs can increase the level of AST, such as lipid-lowering drugs, which may cause liver cell damage, resulting in an increase in the level of AST, sometimes other indicators are normal. 3. Alcohol consumption: If patients drink alcohol for a long time, it may cause alcoholic liver, which may cause the increase of ALT, sometimes other indicators are normal. 4. Physiological elevation: late night, tiredness, strenuous exercise can also cause ALT elevation, which can be recovered on its own. If a patient detects a high level of alanine aminotransferase in physical examination, it is recommended to consult a doctor as soon as possible and conduct further examination to clarify the cause of the disease, do not deal with it blindly, so as not to delay the condition.