Neonatal hyperbilirubinemia, also known as jaundice, is a common newborn condition characterized by high levels of bilirubin in the blood. Bilirubin is a yellow pigment produced during the normal breakdown of red blood cells. When the liver cannot process bilirubin efficiently, it accumulates in the blood and causes yellowing of the skin and whites of the eyes. Some synonyms for neonatal hyperbilirubinemia include neonatal jaundice, bilirubinemia, icterus neonatorum, and newborn jaundice. While jaundice itself is not typically harmful, severe or prolonged cases may require medical treatment to prevent complications such as brain damage.