Synonyms: Bilirubin, Conjugated

Why It Is Done

Evaluate liver function and monitor the development of liver disease Determine whether there is blockage of the bile ducts. Diagnose conditions that cause increased destruction of red blood cells Determine whether newborn infants with neonatal jaundice need treatment.

Test Overview

A bilirubin test measures the amount of bilirubin in a blood sample. Bilirubin is a brownish yellow substance found in bile. It is produced when the liver breaks down old red blood cells. Bilirubin is then removed from the body through the stool (feces) and gives stool its normal brown color.

Bilirubin circulates in the bloodstream in two forms: Indirect (or unconjugated) bilirubin. This form of bilirubin does not dissolve in water (it is insoluble). Indirect bilirubin travels through the bloodstream to the liver, where it is changed into a soluble form (direct or conjugated). Direct (or conjugated) bilirubin. Direct bilirubin is soluble (it dissolves in water) and is made by the liver from indirect bilirubin.

How To Prepare

Adults should avoid eating and drinking for 4 hours before a total bilirubin test.