The normal value of alanine aminotransferase is less than 30U / L, 30U / L is elevated performance, may be due to physiological factors caused by excessive late night, may also be due to pathological factors hepatitis, cirrhosis of the liver and so on. 1. Physiological factors: excessive late night will reduce the damage to the health of the liver, at the same time, if there is overeating, often eat greasy food habits will further damage the liver, showing high alanine aminotransferase. 2. Pathological factors (1) Hepatitis: when suffering from hepatitis, the inflammatory factors in the liver will lead to the abnormal death of liver cells, and the death of liver cells will lead to the release of ALT into the bloodstream, resulting in the elevation of ALT by 30 U/L. (2) Cirrhosis: Patients with cirrhosis show diffuse liver damage, resulting in the destruction of the lobular structure of the liver and the formation of pseudolobules, during which ghrelin is released from the hepatocytes into the bloodstream, which can also lead to an elevation of ghrelin by 30 U/L. An alanine aminotransferase level of 30 U/L is high and prompt treatment under medical supervision is recommended.