The portion of bilirubin processed by the liver to become water-soluble, used to assess liver and bile duct health.
Read moreDirect bilirubin is the fraction of total bilirubin that has been converted in the liver into a water-soluble form to be excreted in bile into the intestines. This conversion allows the body to remove the breakdown products of hemoglobin from old red blood cells. Testing direct bilirubin helps diagnose liver diseases, bile duct obstruction, gallstones, or rare inherited disorders affecting bilirubin excretion. Elevated levels often indicate liver problems or bile duct obstruction, while low levels are rare and usually not clinically significant.