what creates bilirubin
Bilirubin testing checks for levels of bilirubin in your blood. Bilirubin (bil-ih-ROO-bin) is an orange-yellow substance made during the normal breakdown of red blood cells. Bilirubin passes through the liver and is eventually excreted out of the body. Higher than normal levels of bilirubin may indicate different types of liver problems. Occasionally, higher bilirubin levels may indicate an increased rate of destruction of red blood cells (hemolysis). 1  Why it's done.