Neonatal hyperbilirubinemia, which is caused by elevated bilirubin, causes high bilirubin, including the following: 1, excessive destruction of red blood cells: due to the destruction of excessive red blood cells and increased intestinal and hepatic circulation, resulting in elevated serum free bilirubin; 2, liver insufficiency: due to the incomplete development of the liver function of newborns, there is not enough liver enzymes to metabolize bilirubin, low uptake and binding of bilirubin function of liver cells 3, biliary tract insufficiency: because the biliary tract of newborns is not yet fully developed, they cannot excrete free bilirubin in time, which leads to excessive accumulation of bilirubin in the body and induces jaundice; 4, delayed excretion of feces: defecation is one of the main ways to excrete bilirubin from the body, and if the fetal stool is delayed, or if the fetal stool is sticky, which leads to obstruction of bilirubin in excretion, bilirubin accumulates in the body. Bilirubin accumulates in the body, and the hepatic and intestinal circulation increases, leading to the onset of jaundice.