Jaundice Definition - What is Jaundice?

Jaundice (Icterus) is a condition characterized by a yellowing of the skin and the whites of the eyes.
Jaundice is a symptom, not a disease in itself.
The yellow coloration is caused by an excess in the body of the bile pigment bilirubin.
Normally, bilirubin is formed by the breakdown of hemoglobin during the destruction of worn-out red blood cells. It is then excreted by the liver into the bile via the bile ducts.

What causes high bilirubin in the body?

High bilirubin can be caused by:
  • Overproduction of bilirubin;
  • Failure of the liver to metabolize bilirubin or to excrete it;
  • Blockage of the bile ducts.
Overproduction of bilirubin may be caused by the destruction of an excessive number of red blood cells (hemolytic anemia).
The liver then can’t excrete bilirubin fast enough.
This occurs in malaria, thalassemia, and hemolytic disease of the newborn.
Jaundice may also result from various diseases that can affect the liver, such as hepatitis, cirrhosis or cancer.
If the bile ducts become blocked, bile can’t be excreted and jaundice occurs.
The ducts may be blocked by inflammation and in fection (cholangitis); a gallstone (cholelithiasis); or cancer of the pancreas or the common bile duct.
Occasionally a drug such as chlorpromazine may inhibit bilirubin excretion by the liver.

Jaundice in Babies

Mild jaundice occurs as a common and normal condition in newborn babies because at birth there is both a deficiency in the enzyme that helps to excrete bilirubin and also an increased breakdown of red blood cells.
In babies, the condition generally disappears within a few days as the enzyme is formed.
Rarely, this enzyme deficiency can also cause jaundice in adults.

Symptoms of Jaundice

Symptoms of Jaundice depend on the specific cause of the jaundice.
In many forms of the condition, bilirubin is excreted in the urine, which becomes dark brown in color.
If the excretion of bile is obstructed, stools are almost white and the digestion of fat is impaired.
If the condition has been present for some time, intense localized itching may occur due to blockage of the bile ducts.

How are the causes of jaundice diagnosed?

Diagnosis requires special blood tests, in which a physician determines whether the liver is diseased; whether the bilirubin is being correctly metabolized by the liver cells; and whether there is any abnormal breakdown of the red blood cells.
The urine is examined for bilirubin, and the feces for pale coloration (which would indicate an obstruction to bile excretion).
It Is sometimes necessary to perform a liver biopsy to examine Cells under a microscope or to examine the liver, gallbladder, and bile ducts with ultrasound to locate gallstones.