Skip to main content

Serum Bilirubin

Meaning

Serum bilirubin is a yellowish pigment that represents the final catabolic product of heme, which is primarily derived from the physiological breakdown of aged red blood cells. It circulates in the blood in two main forms: unconjugated, which is lipid-soluble, and conjugated, which is water-soluble. Clinical measurement of serum bilirubin is a fundamental test for evaluating liver function, detecting bile duct obstruction, and diagnosing conditions involving excessive red blood cell destruction, such as hemolysis. Elevated levels, known as hyperbilirubinemia, serve as a clear clinical sign of underlying pathology.