The normal value of the alanine aminotransferase level, if tested by the rate method, is about 0-40 U/L. A value of 45 U/L is not considered normal, but it is only mildly elevated and of little clinical value, and continuous monitoring of its changes is required. ALT is an enzyme found mainly in the liver, but also in small amounts in the kidneys, heart, and muscles, and is usually used as one of the indicators of liver function tests. However, if the serum value of ALT exceeds 2.5 times the upper limit of normal (about 100 U/L) for more than half a month, liver and gallbladder disease is usually considered; if it exceeds 20 times the upper limit of normal, about (800 U/L), liver and gallbladder disease is usually recognized as the cause of the disease. If the alanine aminotransferase test result is 45 U/L, it may be caused by a number of non-disease factors, including a history of taking specific medications, such as aspirin, statins, chemotherapy drugs, etc.; accelerated growth and development, such as rapid development of young children may also be mildly elevated; and other extraneous factors, such as strenuous exercise and severe muscle injury. It is recommended that the relevant groups of people regularly and continuously monitor the changes in ghrelin and improve the corresponding risk factors, and make further judgment based on the trend of the values.