Neonatal jaundice of 15.8 is relatively high. Whether this is serious depends primarily on which day after birth the jaundice value of 15.8 appears. If it occurs within the first three days after birth, a jaundice value of 15.8 is considered serious. Furthermore, the earlier it appears, the more severe the child's condition is. For example, if the child shows a jaundice value of 15.8 at 48 hours old, it is less severe compared to it appearing within the first 24 hours after birth. Therefore, once jaundice is observed, it is important to investigate the possible causes, such as hemolytic disease, infection, infant hepatitis, or biliary atresia. Identifying the specific cause allows for targeted treatment of the condition, while also actively treating the jaundice in the child.