The common causes of high alanine aminotransferase are as follows: 1. Viral infections, commonly hepatitis B virus, hepatitis C virus, cytomegalovirus, EBV infection, all of these viral hepatitis can lead to elevated transaminases. 2. Alcoholic liver disease, long-term drinking or short-term heavy drinkers can lead to inflammatory necrosis of liver cells and elevated transaminases. 3. Drug liver damage, taking anti The liver function can be abnormal when taking anti-hyperthyroidism drugs, certain antibiotics or anti-tumor drugs, etc. 4, fatty liver disease, common in patients with moderate to severe fatty liver. 5, certain congenital genetic metabolic diseases, such as hepatomegaly, hepatic glycogen accumulation disease, etc. 6, some people who stay up late for a long time can also have abnormal liver function.