Jaundice is a common clinical symptom and sign of yellowing of the skin, mucous membranes, and sclera due to an increase in the concentration of bilirubin in the blood serum. Normal bilirubin is mainly metabolized by the liver, and the maximum value of bilirubin is 17.1 umol/L, which includes both conjugated and unconjugated bilirubin. If the total bilirubin is between 17.1umol/L and 34.2umol/L, the clinical signs are not too obvious and it is called occult jaundice. If the bilirubin exceeds 34.2umol/L, jaundice may appear in the skin and mucous membranes, as well as in the sclera, which is called overt jaundice. There are many causes of jaundice and different mechanisms of occurrence, which should be treated differently.