Jaundice refers to the yellow discolouration of the sclera and skin (Fig. 1) that is due to hyperbilirubinaemia, occurring at bilirubin levels roughly greater than 50 µmol/L.
Types of Jaundice
There are three main types of jaundice: pre-hepatic, hepatocellular, and post-hepatic.
Pre-Hepatic
In pre-hepatic jaundice, there is excessive red cell breakdown which overwhelms the liver’s ability to conjugate bilirubin. This causes an unconjugated hyperbilirubinaemia.
Any bilirubin that manages to become conjugated will be excreted normally, yet it is the unconjugated bilirubin that remains in the blood stream to cause the jaundice.
Hepatocellular
In hepatocellular (or intrahepatic) jaundice, there is dysfunction of the hepatic cells. The liver loses the ability to conjugate bilirubin, but in cases where it also may become cirrhotic, it compresses the intra-hepatic portions of the biliary tree to cause a degree of obstruction.
This leads to both unconjugated and conjugated bilirubin in the blood, termed a ‘mixed picture’.
Post-Hepatic
Post-hepatic jaundice refers to obstruction of biliary drainage. The bilirubin that is not excreted will have been conjugated by the liver, hence the result is a conjugated hyperbilirubinaemia.
| Pre-Hepatic | Hepatocellular | Post-Hepatic |
| -Haemolytic anaemia -Gilbert’s syndrome -Criggler-Najjar syndrome | -Alcoholic liver disease -Viral hepatitis -Iatrogenic, e.g. medication -Hereditary haemochromatosis -Autoimmune hepatitis -Primary biliary cirrhosis or primary sclerosing cholangitis -Hepatocellular carcinoma | -Intra-luminal causes, such as gallstones -Mural causes, such as cholangiocarcinoma, strictures, or drug-induced cholestasis -Extra-mural causes, such as pancreatic cancer or abdominal masses (e.g. lymphomas) |