A total bilirubin of 31 μmol/L represents a mild elevation, which is characterized by occult jaundice or subclinical jaundice, but the severity of the disease needs to be assessed in conjunction with other indicators of liver function and imaging tests. Total bilirubin is the sum of direct bilirubin and indirect bilirubin, which is an indicator of liver and biliary function, and the increase in total bilirubin can be used to determine the severity of jaundice, and the general total bilirubin value ranges from 1.71μmol/L to 17.1μmol/L. When the total bilirubin is 17.1μmol/L, the total bilirubin is 17.1μmol/L. When the bilirubin is between 17.1 and 34.2 μmol/L, it is difficult to detect with the naked eye and is called hidden jaundice or subclinical jaundice. If the total bilirubin is 34.2 to 171 μmol/L then it is mild jaundice, which is common in hemolytic or hepatocellular jaundice. If the value is 171 to 342 μmol/L it is moderate jaundice, commonly due to hepatocellular or obstructive jaundice. If the total bilirubin is greater than 342 μmol/L it is severe jaundice. It is commonly seen in complete obstructive jaundice. Therefore, a total bilirubin of 31 μmol/L will show hidden or subclinical jaundice, but the severity of the disease needs to be evaluated in conjunction with other indicators of liver function and imaging tests. The total bilirubin value should not be used as the sole basis for judgment. High total bilirubin can be classified as physiologic or pathologic, if it is physiologic, it will decrease automatically. If the total bilirubin of 31μmol/L continues to rise and cannot return to normal, it is recommended to go to the hospital for examination to clarify the cause of the disease, so as to avoid delaying the condition.