Newborns, because of the characteristics of their own bilirubin metabolism, will have a physiological jaundice process after birth, most babies will have neonatal jaundice, jaundice usually begins to appear two to three days after birth, jaundice is evident in 4 to 6 days, and will subside in about 7 to 14 days. This is because bilirubin is closely tested after birth. If the bilirubin level exceeds the phototherapy criteria, prompt phototherapy is required. There are also many clinical cases of early delivery where maternal milk production is insufficient to meet the intake of the newborn, and too little intake results in less excretion and increased reabsorption of bilirubin, leading to breast milk jaundice. For newborns just a few days old, breastfeeding with appropriate sugar water or formula can effectively prevent breast milk jaundice.