How do I differentiate between physiological and pathological jaundice in newborns?

Physiological jaundice typically appears after 24 hours of life, peaks around 3-5 days, and resolves within 1-2 weeks in term infants. It is usually mild and not associated with other signs of illness. Visual inspection should be done in good light, checking skin, sclerae, and gums, but bilirubin levels must be measured to confirm severity as visual assessment alone is unreliable. Physiological jaundice is common, transient, and usually harmless, and breastfeeding can usually continue without interruption.

Pathological jaundice is suggested by jaundice appearing within the first 24 hours of life, rapidly rising bilirubin levels (>8.5 micromol/litre per hour), or very high bilirubin levels (e.g., >340 micromol/litre in term babies). It may be associated with other clinical features such as pale stools, dark urine, or signs of illness. Babies with visible jaundice in the first 24 hours require urgent serum bilirubin measurement and medical review to exclude underlying disease. Additional risk factors include prematurity (<38 weeks), a sibling with neonatal jaundice requiring phototherapy, or exclusive breastfeeding intention.

In summary, the timing of onset, bilirubin kinetics, clinical signs, and risk factors help differentiate physiological from pathological jaundice in newborns. Urgent investigation and management are warranted if jaundice appears within 24 hours or bilirubin levels rise rapidly or exceed treatment thresholds.

All babies with suspected jaundice should have bilirubin levels measured appropriately (serum or transcutaneous depending on age and gestation) and be managed according to established treatment thresholds.

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