Bilirubin Total and Direct Blood Test
A bilirubin test is used to detect an increased level in the blood. It may be used to help determine the cause of jaundice and/or help diagnose conditions such as liver disease, hemolytic anemia, and blockage of the bile ducts.
Description
The bilirubin total and direct test is usually ordered when someone has symptoms of liver disease and is used to differentiate between different types of liver disorders.
Symptoms of liver disease include:
- dark-colored urine
- jaundice
- abdominal pain
- fatigue
- nausea
The components of this test are:
- Total bilirubin- made up of direct and indirect form of the substance
- Indirect bilirubin (also called Unconjugated) —when heme is released from hemoglobin, it is converted to unconjugated bilirubin. It is carried by proteins to the liver. Small amounts may be present in the blood.
- Direct bilirubin (also called conjugated)—formed in the liver when sugars are attached (conjugated) to bilirubin. It enters the bile and passes from the liver to the small intestines and is eventually eliminated in the stool. Normally, no conjugated bilirubin is present in the blood.
