Bilirubin (jaundice)

Bilirubin direct and bilirubin total are measured in this test.

What is jaundice?

Jaundice (icterus) is not a disease in itself, but a symptom of various disorders of the liver and gallbladder. Jaundice is caused by excessive levels of the substance bilirubin in your blood. Bilirubin is a waste product that is produced when a protein is broken down from your red blood cells. It has an intense yellow color, which means that with an increased concentration of this substance in your blood you will literally see yellow.

The following symptoms can occur with jaundice:

• Yellowish discolouration of your mucous membranes (whites of the eyes, gums)
• Yellowish discoloration of your skin
• Dark brown colored urine
• Pale stools

Cause of jaundice

Normally, the substance bilirubin is processed by the liver and ends up in the bile fluid. It is then worked out of your body through your stool. This process can be disrupted by various causes.

The most common causes are:

Increased breakdown of red blood cells. This is the case, for example, after heavy bleeding. The liver can no longer cope with the supply of bilirubin and therefore too much bilirubin remains in the blood.

Disorders of liver function. Several conditions can lead to a disturbance in liver function. Examples of disorders are: cirrhosis of the liver, excessive alcohol consumption and metabolic disorders. The bilirubin can then not be processed and excreted in the right way, leaving an increased concentration of the substance in your blood.

Blockage in the drainage of bile fluid. If the bile ducts are blocked by such things as gallstones, tumors or inflammation, the bile fluid formed in the liver can no longer be drained. This causes pressure to build up and the bilirubin to re-enter your blood.

There are also a number of specific situations in which jaundice can occur:

• Disease of Weil
• Toxoplasmosis
• Side effect of certain medications
• In newborn babies

In almost 80 percent of all babies, the skin has a yellowish color between the 3rd and 5th day after birth. Usually this form of jaundice disappears on its own within a week or two. If it is expected that the jaundice in the baby will increase significantly, light therapy can be used. The child is then placed under white and blue fluorescent tubes for several days. The excess amount of bilirubin is then broken down.

What is the difference between Billirubin Direct and Bilirubin Total?

There are two types of bilirubin:

• indirect or non-conjugated bilirubin (for transformation in the liver)
• direct or conjugated bilirubin (after transformation in the liver)

Together, these two are called total bilirubin.

An increase in direct bilirubin indicates a blockage in the bile ducts or liver damage.
An increase in indirect bilirubin is an indication that too many red blood cells are being broken down, such as in hemolytic anemia. together, these two values form the Bilirubin Total.

Bilirubin concentrations in serum are age- and sex-dependent.