Jaundice

What is it? / Causes
Tests
Treatment

What is it?
Jaundice is a yellowing of the skin, whites of the eyes, and body fluids. It is caused by an increase in the amount of bilirubin in the blood. Bilirubin is a yellow pigment that is produced from the breakdown of heme, mostly from haemoglobin in red blood cells (RBCs). It is transported by the blood to the liver, where it is linked with a sugar by an enzyme (conjugated) so that it can be excreted in bile, eventually reaching the small intestine. Jaundice may arise from a problem at any point in the pathway and is usually a sign that there is a problem that needs to be addressed.

Examples of common conditions that may cause jaundice

Acute hepatitis: liver inflammation due to a variety of causes including hepatitis A, B, C, D, and E viral infections, alcohol abuse, and some medicines and toxins.

Obstruction of the bile ducts inside and/or outside the liver: may be due to a stone, damage and scarring in the late stages of cirrhosis, cancer in the liver, or biliary atresia, a congenital condition associated with abnormal development or the bile ducts. It leads to the back-up and pooling of the bile behind the obstruction and to the increase of conjugated bilirubin in the blood. Gallstones can block bile ducts and pancreatic cancer can sometimes lead to a blockage in the bile ducts outside the liver.

Haemolytic anaemia: may be caused by an abnormal haemoglobin variant in the RBCs, malaria, an autoimmune process or any other conditions that lead to a significant increase in the destruction of red blood cells and to an increase in the production of bilirubin. The jaundice is mild and due to unconjugated bilirubin..

Gilbert’s syndrome: about 3% of the UK population have this condition. It is associated with decreased bilirubin conjugation in the liver due to an inherited decrease in enzyme activity and therefore reduced excretion in the bile. Those affected may have temporary mild jaundice during times of illness or stress caused by increases in their unconjugated bilirubin levels.

Physiological (normal) jaundice: mild jaundice is seen in more than 50% of newborns due to the immaturity of the baby's liver enzyme needed to conjugate bilirubin. It usually appears at 2 to 4 days and disappears by 7 to 10 days. If the jaundice appears early, persists or is severe the infant will be investigated for other causes and is likely to need treatment.

Examples of more rare conditions that may cause jaundice

Crigler-Najjar syndrome: an inherited condition that may lead to high bilirubin concentrations; a gene mutation leads to a deficiency in the enzyme necessary for bilirubin conjugation.

Dubin-Johnson syndrome: an inherited disorder that impairs the secretion of bilirubin from liver cells after it has been conjugated; patients may have intermittent jaundice.

Rotor’s syndrome: an inherited cause of mild intermittent jaundice; similar to Dubin-Johnson without the retention of bilirubin in the liver cells.

Pseudojaundice: the skin of a person may turn yellowish when they eat large quantities of carrots, pumpkin or melon due to the presence of beta-carotene; a temporary and benign condition not related to bilirubin or bile