What is the difference between pathological jaundice and physiological jaundice?

　　Under normal circumstances, pathological jaundice and physiological jaundice differ in terms of onset time, duration, severity, causes, and treatment methods. A detailed analysis is as follows:

　　1. Onset time: Physiological jaundice usually appears 2 to 3 days after birth, following the normal pattern of bilirubin metabolism in newborns. Pathological jaundice occurs earlier, possibly within 24 hours after birth, or may reappear after the resolution of physiological jaundice.

　　2. Duration: Physiological jaundice lasts for a shorter duration, generally no more than 2 weeks in full-term infants and no more than 4 weeks in preterm infants, and can resolve spontaneously. Pathological jaundice lasts longer, persisting beyond 2 weeks in full-term infants and beyond 4 weeks in preterm infants, or recurring after resolution.

　　3. Severity: Physiological jaundice is mild, with the skin appearing light yellow, mainly affecting the face and trunk, while the distal extremities are less involved. Pathological jaundice is severe, with the skin appearing dark yellow or golden yellow, spreading throughout the body including the palms and soles.

　　4. Causes: Physiological jaundice is caused by physiological factors such as excessive bilirubin production and immature liver metabolism in newborns, and is considered a normal physiological phenomenon. Pathological jaundice is caused by various pathological factors such as biliary atresia, infection, hemolysis, and liver dysfunction, and the specific cause should be identified.

　　5. Treatment: Physiological jaundice generally does not require specific treatment; enhancing feeding and promoting defecation can help eliminate bilirubin, and jaundice resolves spontaneously. Pathological jaundice requires targeted treatment based on the underlying cause, such as phototherapy, medication, or surgical treatment, to reduce bilirubin levels and prevent complications.

　　If a newborn develops jaundice, the onset time, duration, and severity of jaundice should be closely observed. If pathological jaundice is suspected, prompt medical evaluation is necessary to identify the cause and follow the physician's instructions for treatment to prevent neurological damage caused by excessive bilirubin levels.