Jaundice developing after 24 hours of life is usually what?

• A. Pathologic
• B. Not physiologic
• C. Physiologic
• D. Common variation

Answer: (C)

Physiologic jaundice is the normal, self-limited rise in bilirubin that most newborns experience. It typically appears after the first 24 hours of life—often around days 2–3—peaks around day 3–5, and generally resolves by about day 7–10 in term babies (longer in preterm infants). The rise comes from a combination of a briefly immature liver detoxifying system and increased bilirubin production, along with more bilirubin recirculation in the gut. Because it follows a predictable pattern and resolves without treatment, jaundice that shows up after 24 hours is considered physiologic rather than a problem needing intervention. Pathologic jaundice, by contrast, would present earlier (often within the first 24 hours), rise more rapidly, or persist longer than the typical first-week window, and is associated with illness or other risk factors.