What is the normal range for physiological jaundice?
Jul 10, 2025
Source: Cainiu Health
Dr. Shen Yonghua
Introduction
The normal range of physiological jaundice should be determined according to the infant's age in days. In full-term infants, jaundice typically appears on the 2nd to 3rd day after birth, peaks on the 4th to 5th day, and if the serum bilirubin level remains within 221 μmol/L and rises no more than 5 mg/dL per day during this period, it is generally considered within the normal range. The jaundice usually resolves spontaneously within 7 to 10 days and does not require specific treatment.
Under normal circumstances, the normal range for physiological jaundice should be determined according to the infant's age in days. Generally, serum bilirubin levels in full-term infants do not exceed 221 μmol/L, while in preterm infants they do not exceed 257 μmol/L. If concerned, it is recommended to seek medical advice earlier. Detailed analysis is as follows:
Jaundice typically appears in full-term infants 2–3 days after birth, peaks at 4–5 days, and if the serum bilirubin level remains within 221 μmol/L with a daily increase of no more than 5 mg/dL, it is generally considered within the normal range. The jaundice usually resolves spontaneously within 7–10 days and does not require specific treatment.
Due to less mature liver development, jaundice in preterm infants tends to appear and resolve slightly later. The peak serum bilirubin level may be slightly higher, but if it remains below 257 μmol/L, it is generally considered physiological jaundice. It usually gradually resolves within 2–4 weeks, during which close monitoring of bilirubin level changes is necessary.
When observing jaundice, attention should be paid to the extent of skin yellowing and the rate of resolution. If bilirubin levels exceed the normal range or the jaundice persists, timely medical evaluation is necessary to rule out the possibility of pathological jaundice.
