Most newborns can develop yellow skin stains within a week of birth. This is due to the presence of a substance called bilirubin in the baby’s body. An increase in bilirubin in the body can cause yellow staining of the skin and sclera, a phenomenon known as jaundice. Neonatal jaundice is one of the common symptoms of the newborn period, especially in early neonates, and the causes of jaundice are many and complex and can lead to bilirubin encephalopathy (nuclear jaundice), which often causes death or serious sequelae. Newborns with severe jaundice should be alerted to the occurrence of nuclear jaundice, especially in immature children, the younger the age, the higher the incidence, generally within 12 to 48 hours after the onset of severe jaundice, depression, drowsiness, weakness in sucking milk, hypotonia, vomiting, not eating milk and other symptoms, at this time, such as timely treatment, can be completely recovered. First, how can parents determine the degree of jaundice in newborns? We can observe the degree of skin yellowing in newborns under natural light, and press the skin surface of the harder parts of the body, such as the forehead, chest or thighs, with the thumb, if only the face yellowing for mild yellowing; trunk skin yellowing for moderate yellowing; the same way to observe the limbs and hands and feet, if yellowing also appears, that is, severe yellowing, should be promptly checked and treated at the hospital. Second, the causes of neonatal jaundice neonatal physiological jaundice can subside on its own, but pathological jaundice is a group of diseases consisting of many causes, which must be detected and treated as early as possible. Several common causes of jaundice are: hemolytic jaundice, infectious jaundice, obstructive jaundice, breast milk jaundice, etc. Pathological jaundice, regardless of the cause, can cause severe “nuclear jaundice”, which has a poor prognosis, in addition to neurological damage, can cause death in severe cases. Third, the classification of neonatal jaundice 1, physiological jaundice most full-term infants in the postnatal 2-3 days jaundice, 5-7 days the heaviest, 10-14 days to subside, premature infants can be delayed to 3-4 weeks, the general situation is good, full-term infants serum bilirubin <205.2umol / L (12mg / dl), premature infants serum bilirubin <256.5umol / L (15mg / dl). Red blood cells, hemoglobin and reticulocytes were in the normal range, there was no bilirubin or excess urobilinogen in the urine, and liver function was normal. This jaundice is physiological jaundice and parents need not be nervous. At present, serum bilirubin <257umol/L (15mg/dl) in preterm infants is considered inappropriate as the upper boundary of physiological jaundice, because bilirubin encephalopathy may occur even in smaller preterm infants with bilirubin <171umol/L (10mg/dl). About 50% of full-term infants and 80% of preterm infants can develop physiological jaundice. 2, pathological jaundice (1) jaundice within 24h; (2) jaundice is heavy, fast development, serum bilirubin > 205umol / L (12mg / dl) or daily rise > 85umol / L (5mg / dl). (3) Jaundice persists for too long (>2 weeks in term infants, >4 weeks in preterm infants) or recedes and recurs, and progressively worsens; (4) serum conjugated bilirubin >26umol/L (1.5mg/dl). 3, breast milk jaundice (1) breastfeeding alone. (2) without any clinical symptoms, good growth and development. (3) Non-hemolytic unconjugated bilirubin is increased. (4) Normal liver function, no anemia. (5) Peak jaundice is often 7-10 days after birth and can last 6-12 weeks. (6) 2 to 3 days after the suspension of breast milk, jaundice can quickly subside, bilirubin can be reduced by 50%. (7) Without any treatment, jaundice can gradually subside.