Yellowing of the skin and whites of the eyes, brought on by an accumulation of the brown-yellow pigment bilirubin in tissues and blood. Jaundice is the key sign of many disorders of the biliary system and liver. Many otherwise normally healthy babies are affected shortly by jaundice briefly after birth.
Types and causes
Bilirubin is formed from haemoglobin (the oxygen carrying pigment in red blood cells) when old red cells are broken down, mostly by the spleen. It is absorbed by the liver, where it is made soluble in water and excretes in the bile.
There are three main types of jaundice: obstructive, haemolytic and hepatocellular.
In obstructive jaundice, also known as cholestatic jaundice, bile is unable to leave the liver due to bile duct obstruction, which can be caused by a tumour anywhere in the duct or by gallstones. Obstructive jaundice can also arise if the bile ducts are underdeveloped (as seen with biliary atresia) or have been eradicated by disease. Cholestasis (stagnation of bile in the liver) this arises and bilirubin overflows into the blood.
In haemolytic jaundice, too much bilirubin is made for the liver to handle. This condition arises from excessive haemolysis (breakdown of red blood cells), which can have a range of possible causes.
In hepatocellular jaundice, bilirubin builds up because it is stopped from passing from liver cells into the bile. This type of jaundice is often due to acute hepatitis (inflammation of the liver) brought on by taking particular drugs or by liver failure.
Bloods tests, and sometimes a liver biopsy (removal of a sample of tissue for analysis), can be carried out to classify the cause of the jaundice. Investigation of the bile duct can be undergone using imaging techniques, such as ERCP and MRI. Treatment is then given for the underlying cause.