Direct Bilirubin Liver Test - Direct Bilirubin Test

Measuring the level of direct (conjugated) bilirubin in the blood serum. Direct bilirubin is bilirubin that has been processed in the liver and conjugated to glucuronic acid, making it water-soluble so it can be excreted via bile into the intestines. Direct bilirubin levels are elevated primarily when there is a disruption in the secretion of bile from liver cells into the bile ducts, or when there is an obstruction in these ducts (cholestasis), such as in gallstones or bile duct tumors.