In normal newborn babies, because the liver function is not yet developed, there is often a slight jaundice in the first week after birth, called “physiological jaundice”, which appears from the second to the fourth day and reaches its peak on the fourth to the fifth day on average, and disappears within a week to two weeks. (The value of jaundice can be determined by a physician.) Physiological jaundice does not affect the health of the baby. However, if the jaundice is too severe, lasts too long, progresses too quickly, or recedes and rises again, it is necessary to be alert to the presence of disease, which is called “pathological jaundice”. The common causes of pathological jaundice include infections (e.g. hepatitis, sepsis, intrauterine infections, etc.), hemolytic jaundice due to blood group discordance between mother and baby (ABO hemolysis and RH hemolysis), internal or subcutaneous bleeding, etc. Pathological jaundice can have a serious impact on the health of the newborn and must be taken seriously by parents. For example, if the bilirubin index exceeds 20 mg/dl, the most important nucleus basalis in the baby’s brain will be damaged and necrotic, which may result in cerebral palsy, making the baby’s intelligence, hearing, vision and mobility impaired for life; if there is hepatitis or prenatal infection, it can cause serious liver damage to the baby, and once Rh hemolysis occurs and is not treated properly, it often results in the death of the newborn, with very serious consequences. The consequences are very serious.