The normal range of ALT is 0-40 U/L. In normal people, if the patient is tired, stays up late, drinks alcohol or is depressed, or has a menstrual period, there will be a transient increase in liver function, that is, an increase in ALT. If the elevation is mild, the patient does not need to be concerned about it, but should take more rest, do not drink alcohol, do not stay up late, drink more water and regulate the mood. If the percentage of elevation is too high, more than 3-4 times the normal value, we should consider whether the patient has organic pathology. For example, if the patient has hepatitis, alcoholic hepatitis, jaundice or liver necrosis due to other reasons, if necessary, the upper abdominal ultrasound should be checked to determine whether the patient has biliary obstruction and whether intrahepatic jaundice caused by biliary obstruction further causes the patient’s liver insufficiency and liver cell necrosis.