Bilirubin is a by-product of the process in which haemoglobin, a protein in red blood cells is broken down. The liver is responsible for removing bilirubin in the blood, therefore when levels are elevated, it can be the sign of a liver disorder. Signs of elevated levels of bilirubin include yellowing of the skin, dark urine, vomiting, abdominal pain, or chronic fatigue.
Elevated Levels in Newborns
Jaundice is a common disorder that occurs in newborns. A newborn's liver is not yet fully developed, therefore the infant is not able to sufficiently process the red blood cells that are produced when he or she is born. Jaundice occurs when bilirubin levels reach 2.5 mg/dl or greater. This can manifest itself in the baby's skin appearing yellow in colour. As extremely high bilirubin levels are associated with brain damage, it is important to seek medical treatment for jaundice.
Blockage of Bile Ducts
Bile is the by-product released by the liver that contains bilrubin as well as cholesterol, bile salts, and other waste products. If the bile ducts are blocked due to causes such as gallstones, pancreas or bile duct tumours, cysts, inflammation, or injury due to surgery; bilirubin builds up in the liver and causes increased levels.
Liver disease such as cirrhosis, which is due to excessive alcohol consumption, or hepatitis, which affects liver function. Both of these disorders contribute to elevated bilirubin because these disorders kill off liver cells and cause scarring. The decrease in liver cells can impair liver function, resulting in increased bilirubin levels.
Inherited Health Disorders
Some genetic disorders affect the liver's ability to function properly or process bilirubin, such as Crigler/Najjar syndrome, Erthroblastosis fetalis, and Gilbert's disease. While each affects the liver in different manners, all involve the inability to properly break down bilirubin in the body, increasing levels.