Jaundice is a common phenomenon during the neonatal period, and more than half of all newborns can have varying degrees of clinical yellow bile: this is known as “neonatal jaundice”. Many first-time parents are alarmed by the sight of their child’s yellowish complexion 2-3 days after birth. Jaundice in older children or adults is pathological, but in newborns, it is mostly normal. Only a few cases are due to disease, called pathological jaundice, and pathological jaundice may endanger the life of the newborn or cause serious sequelae. Physiologic jaundice, i.e., most full-term newborns will have yellowing of the face 2-3 days after birth, more pronounced on day 4-5, and the trunk and extremities can also be yellow, which begins to gradually decrease after day 5-6 and can disappear completely by day 7-10. In premature infants, jaundice recedes later, disappearing in about 10-15 days, and in a few cases up to 3 weeks or more. The degree of jaundice is not heavy and has little effect on the child’s body, so no special treatment is needed. During the jaundice period, breastfeeding can be done diligently so that the stools are passed more often. You can also let the baby sunbathe through a glass, and these methods can reduce the degree of jaundice. Of course, some cases are pathological and must be given high priority. 1, as soon as the child is born (within 24 hours), there is jaundice, and rapidly deepening, there is pale anemia, this is due to the mother and child blood type incompatibility caused by neonatal hemolytic disease, need to be sent to the hospital urgently to rescue. 2, if the jaundice is progressive or intermittent deepening, accompanied by fever, blue and gray, refused to eat milk, nausea and vomiting and other symptoms of poisoning, may be suffering from neonatal sepsis. 3, no jaundice at birth, 1-2 weeks or longer after birth jaundice, progressive deepening, eating milk is still good, a few days after birth stool is still light yellow, but with the deepening of jaundice, stool gradually becomes white clay-like, this is a kind of obstructive jaundice, need to send to the hospital for detailed examination, may have congenital atresia of the biliary tract. In conclusion, any newborn with jaundice that appears too early, or lasts too long, or is too jaundiced, or is accompanied by other symptoms such as fever, not eating milk, poor spirit, convulsions, and lighter stool color, should be considered pathological jaundice and sent to the hospital immediately for diagnosis and treatment. As soon as jaundice appears in a newborn, it is best to consult a neonatologist or pediatrician to determine whether it is physiological or pathological and to decide whether to hospitalize the baby or intensify observation. It is important to note that, unlike children and adults, the vast majority of early neonatal jaundice due to various causes is due to increased unconjugated bilirubin. Unconjugated bilirubin is neurotoxic and can cross biological membranes and the blood-brain barrier. When unconjugated bilirubin reaches a certain level or when premature infants or newborns have hypoxia or acidosis, it can cause bilirubin encephalopathy, resulting in central nervous system damage, called nuclear jaundice. This disease can have serious consequences, with a high mortality rate, and most survivors are left with intellectual disability, hearing impairment, cerebral palsy and other sequelae, a serious threat to the health and life of newborns, should be given great attention. Therefore, for the sake of the child’s life and health, neonatal jaundice must be promptly seen by a doctor, because bilirubin encephalopathy (nuclear jaundice) is a completely preventable disease. The key is to see a doctor in time and to treat the jaundice before it reaches the level of bilirubin encephalopathy, which can be prevented. If the diagnosis is too late and bilirubin encephalopathy has already occurred, there is nothing the doctor can do.