What causes physiological jaundice in newborns?

Physiological jaundice in newborns primarily occurs due to the rapid breakdown of red blood cells, also known as hemolysis. In newborns, especially in the first few days of life, red blood cells have a shorter lifespan than in older children and adults. This increased breakdown leads to an elevation in the levels of bilirubin, a byproduct of hemoglobin metabolism, in the bloodstream.

As newborns transition from fetal to neonatal life, their bodies may not efficiently process and excrete bilirubin, contributing to jaundice. This condition typically resolves as the infant's liver matures and is able to conjugate and eliminate bilirubin more effectively.

Other factors related to bilirubin production and liver function can play roles in jaundice, but in the context of physiological jaundice, the focus is on the rapid breakdown of red cells as the primary driver of increased bilirubin levels.