Although risk factors such as hemolysis, hypoxia, hypoglycemia, prematurity or infection must always be considered, the main criteria of a potential severity of neonatal hyperbilirubinémia is the serum concentration of free bilirubin, or if it cannot be determined, the bilirubin/albumin ratio. However in common practice the therapeutic decisions are usually based upon the level of total bilirubin serum concentration. Phototherapy and albumin infusions control most of severe hyperbilirubinemias, and the use of exchange transfusion is rare nowadays.