Jaundice is a symptom of an underlying condition rather than a disease in itself. Jaundice is caused by an accumulation of a yellow–green substance called bilirubin in the tissues of the body, which causes a yellowing of the skin, eyes and mucous membranes.
The condition can also cause other symptoms such as abdominal pain, itchy skin, headache, swollen abdomen, dark urine and pale stools.
Jaundice is categorized into three different forms, depending on what the underlying cause of the bilirubin build-up is. The different types of jaundice are described below.
- Pre-hepatic jaundice – Here, the bilirubin level is disrupted prior to transportation of blood to the liver. Examples of conditions that cause this type of jaundice are hemolytic anemia and sickle cell disease.
- Hepatocellular jaundice – Here, the disrupted bilirubin is caused by a problem in the liver and examples of conditions that cause this include liver cirrhosis and Gilbert’s syndrome.
- Post-hepatic jaundice or obstructive jaundice – Here, bile (and therefore the bilirubin contained inside it) is obstructed and prevented from draining into the digestive system from the gallbladder. Examples of factors that may cause this are tumors and gallstones.
For each type of jaundice, the clinical features of the disease are different, as outlined below.
- Pre-hepatic jaundice – There is no bilirubin present in the urine and there is an increase in the level of unconjugated bilirubin in the blood.
- Hepatocellular jaundice – Conjugated bilirubin is present in the urine. The plasma albumin level is reduced, but globulins are raised in response to an increase in antibodies. The urine is dark-colored and the stools are either normal or pale. Enzymes alkaline phosphatase, alanine transferase and aspartate transferase are all raised.
- Post hepatic or obstructive jaundice – The blood level of conjugated bilirubin is raised; the urine is dark-colored and the stools are pale. Alkaline phosphatase, alanine transferase and aspartate transferase levels are all raised.