Not every newborn baby will have jaundice. Jaundice is mainly due to the excessive accumulation of bilirubin in the body of newborns, which can be divided into physiological jaundice and pathological jaundice. Physiological jaundice: Most of the jaundice will appear 2~3 days after the birth of newborns, and it will be more serious in 4~5 days after the birth, which is only a temporary phenomenon, and it will subside in 7~10 days for full-term babies, and it may subside in 2~4 weeks for preterm babies. Bilirubin does not rise more than 8.5umol/l per hour, and the newborn has no other abnormal discomfort. Pathologic jaundice: it usually appears within 24 hours after birth and lasts for a longer period of time, lasting more than 2 weeks in term infants and more than 4 weeks in preterm infants. Bilirubin rises more than 8.5 umol/l per hour, and jaundice may recur, which is more serious. Jaundice does not occur in normal newborns, and even if it does, it is physiologic. However, if newborns have pathological jaundice, they should go to the hospital for treatment in time, so as to avoid the brain nerve damage of newborns due to the rapid increase of bilirubin, resulting in sequelae.