In obstructive processes, is conjugated bilirubin typically increased or decreased?

In obstructive processes, conjugated bilirubin typically increases due to the blockage of bile flow, which can occur in conditions such as biliary obstruction from gallstones, tumors, or strictures. When the bile ducts are obstructed, the normal flow of bile is disrupted, causing conjugated bilirubin, which is water-soluble and primarily produced in the liver from the metabolism of hemoglobin, to accumulate in the bloodstream.

The liver produces conjugated bilirubin, and under normal circumstances, this substance is excreted into the bile and eventually into the intestines. However, when an obstruction occurs, the conjugated bilirubin cannot be properly excreted, leading to an elevated level in serum. This is in contrast to unconjugated bilirubin, which typically remains unchanged or decreases in such obstructive situations since it is not directly associated with bile flow.

Understanding this mechanism is crucial in diagnosing and managing liver and biliary disorders, highlighting the importance of recognizing the patterns of bilirubin levels in various conditions.