Aminotransferases are commonly used to test liver function and exist in liver cells. When liver cells become inflamed and necrotic, aminotransferases enter the bloodstream and are examined by blood, aminotransferases will rise, which can indicate the presence of liver cell damage, but the level of aminotransferases does not represent the severity of the disease. In patients with severe hepatitis, transaminases can be normal, but jaundice indicators are significantly elevated, which is clinically referred to as the yellow enzyme separation phenomenon, indicating a poor prognosis. When the examination reveals elevated transaminases, the cause should be clarified and appropriate treatment should be given, such as viral hepatitis, drug-related hepatitis, fatty liver, alcoholic hepatitis, all of which can cause elevated transaminases, and there are also unexplained elevated transaminases, which need further clarification by liver aspiration examination.