Bilirubin (Total, Direct and Indirect)

What is Bilirubin (Total, Direct and Indirect)?
A kidney, ureter, and bladder (KUB) X-ray helps to visualize the organs of urinary and gastrointestinal systems. It is performed to determine an intestinal blockage, foreign objects in the stomach, tumors, kidney stones and gallstones. It can also provide information regarding the size, shape, and position of the kidneys, ureters, and bladder. This X-ray is advised to people complaining of persistent or acute abdominal pain.

A KUB X-ray is primary evaluation of the urinary tract before performing any other diagnostic procedures.

Why is Bilirubin (Total, Direct and Indirect) done?
The Bilirubin (Total, Direct and Indirect) test is done in case of signs and symptoms of:

• Liver damage
• Liver disease
• Bile duct blockage
• Hemolytic anemia
• Liver-related metabolic problems
• Jaundice in newborns

What does Bilirubin (Total, Direct and Indirect) Measure?
The Bilirubin (Total, Direct and Indirect) measures the amount of bilirubin present in the blood of a person. Bilirubin is an orange-yellow waste pigment produced by the normal breakdown of heme. The heme is a component of hemoglobin and is found in red blood cells. The liver processes the bilirubin and eliminates it from the body.

The life span of red blood cells is about 120 days. The heme which is released from the hemoglobin is converted into bilirubin which is called unconjugated bilirubin. It is then carried to the liver by proteins, where it gets attached to sugars and becomes conjugated bilirubin. The conjugated bilirubin enters the bile from the liver and passes to the small intestine where it is broken down by the bacteria and further eliminated in the stool. These breakdown products of bilirubin are responsible for giving the characteristic brown color to the stool.

A healthy adult body produces approximately 250 – 350 mg of bilirubin daily. About 85% of bilirubin comes from damaged or degraded RBCs while the remaining amount comes from the bone marrow or liver. The small amount of unconjugated bilirubin is released in the blood normally, but conjugated bilirubin is not present in the blood.

Both these forms of bilirubin can be measured or estimated and total bilirubin (sum of direct and indirect bilirubin) may be reported. In case there is an increase in levels of bilirubin, there will be yellowing of the skin and white of the eyes, giving the appearance of jaundice.