An alanine aminotransferase of 1000 U/L or more means that liver function is severely impaired, but it is not certain what disease is causing it. Albuminous aminotransferase is one of the indicators of liver function, and the normal reference range is from 0 to 40 U/L. An albuminous aminotransferase of 1000 U/L or more means that the result is severely elevated, which means that liver function is severely impaired. Diseases such as viral hepatitis, alcoholic hepatitis, steatohepatitis, cirrhosis, liver cancer, etc. may lead to severe destruction of liver cells, and a large amount of aminotransferases will be released into the bloodstream, resulting in the phenomenon of alanine aminotransferase 1000 U/L. If the phenomenon of 1000U/L AST is present, further examination of liver ultrasound, CT, tumor markers, pathological biopsy and other items are needed to find out the cause and then actively treat under the guidance of the doctor.