Elevated bilirubin in liver function can be harmful, and if a newborn has elevated bilirubin, care should be taken to rule out pathological jaundice. If the bilirubin elevation is too pronounced, it may cause nuclear jaundice, also known as bilirubin encephalopathy, which not only affects the growth and development of the newborn, but may also cause mental retardation or even death in the newborn. In adults, elevated bilirubin may be caused by liver cell damage, impaired bile excretion, or excessive red blood cell destruction. Regardless of the disease, elevated bilirubin can cause varying degrees of damage to the body. If there is extensive hepatocellular damage or even hepatocyte necrosis, acute liver failure can result. Impaired bile excretion due to biliary obstruction can cause intrahepatic biliary stasis and eventually lead to the formation of biliary cirrhosis. Cirrhosis can cause portal hypertension, resulting in a series of serious complications such as upper gastrointestinal bleeding, hepatic encephalopathy, hepatorenal syndrome, hypersplenism and intractable ascites, which endanger patients’ lives.