Neonatal jaundice is generally divided into physiological jaundice and pathological jaundice. Physiological jaundice is usually considered a normal phenomenon, where the baby's jaundice can naturally recede without much impact on the baby. If it is pathological jaundice, it means that the jaundice level is high, indicating a pathological condition. Pathological jaundice can be further divided into several types, the most common being elevated direct bilirubin and elevated indirect bilirubin, each with different causes. Common causes of jaundice include increased indirect bilirubin due to infections, hemolysis, and mother-infant blood type incompatibility, such as ABO incompatibility where the mother is type O and the baby is not, or the mother has HR-negative blood and the baby has HR-positive blood. Other factors include reduced thyroid function, enzyme deficiencies such as G6PD deficiency, various types of bleeding like gastrointestinal bleeding, intracranial bleeding, or asphyxia at birth. Conditions like hypoxia or acidosis in the baby can also lead to increased jaundice. Additionally, liver function damage due to viral infections like hepatitis B, cytomegalovirus, and other infectious diseases such as syphilis, as well as other viruses like rubella virus and herpes virus can elevate jaundice levels. Developmental abnormalities of the biliary tract, commonly biliary atresia or congenital bile duct dilation, can cause elevated conjugated bilirubin levels. The causes of jaundice are complex, and some causes might remain unidentified. However, if the baby's general condition is good and the jaundice is manageable, it generally does not affect the baby. If jaundice levels are high, it is advised to visit a hospital where doctors can conduct relevant tests based on the baby's specific condition to determine if treatment is needed.