Hyperbilirubinemia of the newborn, commonly known as jaundice, is a common condition that occurs in newborn infants. It is caused by high levels of bilirubin in the blood and can cause yellowing of the skin and eyes. There are several synonyms for hyperbilirubinemia of the newborn, including neonatal jaundice, physiologic jaundice, and icterus neonatorum. Physiologic jaundice refers to a normal process that occurs in most newborns as their liver develops, while icterus neonatorum is a more severe form of jaundice that may require medical intervention. Other synonyms for hyperbilirubinemia include bilirubinemia, cholestatic jaundice, and unconjugated hyperbilirubinemia.