 Genetics play a major role in the development of very high unconjugated bilirubin plasma concentrations in newborns, which can lead to neurological damage. Mutations in the genes encoding glucose, 6-phosphate dehydrogenase, G6PD, and uridine 5-bac slash diphospho, glucuronosiltransferase, UG2, 1a1 are the most common causes of these elevated bilirubin levels. Additionally, low gestational age, excessive weight gained by the mother, and other factors such as prolonged rupture of membranes, large hematomas, and neonatal sepsis can increase the risk of developing neonatal hyperbillirubinemia. This article was authored by Jamana Bank One, Gorn Pan Gornso One, Pymnara Pyroworinan, and others.