Bilirubin Total

The Bilirubin Total 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. This conjugated bilirubin enters the bile from the liver and passes to the small intestine. Here, it gets broken down by the bacteria and further gets 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.

Small amount of unconjugated bilirubin is released in the blood normally, but there is no virtual presence of conjugated bilirubin in the blood. 

Both the forms of bilirubin can be measured or evaluated by the laboratory tests, and total bilirubin (sum of conjugated or unconjugated 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.