It is known as unconjugated bilirubin. Breaking down of hemoglobin (protein in RBC’s) makes bilirubin.
The liver removes bilirubin from the body, so measuring the bilirubin helps check the working of the liver. This test is needed if a total bilirubin blood test is abnormal. It may be done as a part of a routine check-up or done in order to check for blood diseases
The testing is done by a sample of blood.
Indirect and direct bilirubin make up total bilirubin. So when the total is abnormal then these need to be checked. Indirect bilirubin is the total minus the direct bilirubin. Normal values for total bilirubin are 0.3 to 1’omg/dL and for direct bilirubin 0 to 0.3 mg/dL