Bilirubin is a yellow pigment formed during the breakdown of hemoglobin from red blood cells.

It exists in two forms:

Unconjugated (indirect) bilirubin – produced from hemoglobin breakdown, transported to the liver.

Conjugated (direct) bilirubin – processed in the liver and excreted in bile.

Clinical uses include:

Diagnosing liver diseases (hepatitis, cirrhosis, liver failure).

Detecting bile duct obstruction.

Evaluating hemolytic anemia and neonatal jaundice.

Monitoring patients with chronic liver conditions.

Often performed alongside Liver Function Tests (LFTs) for comprehensive evaluation

Analyte: Total bilirubin, direct bilirubin, and indirect bilirubin in serum (mg/dL).

Normal Range (varies by lab):

Total bilirubin: 0.3 – 1.2 mg/dL

Direct bilirubin: 0.0 – 0.3 mg/dL

Indirect bilirubin: 0.2 – 0.9 mg/dL

Abnormal Findings:

Elevated direct bilirubin: Suggests liver disease or bile duct obstruction.

Elevated indirect bilirubin: Suggests hemolysis or impaired liver conjugation.

Clinical Use:

Provides a direct marker of liver and bile metabolism.

Helps guide diagnosis, monitoring, and treatment of hepatic and hematologic disorders.

Supports hepatology, gastroenterology, pediatrics, and internal medicine evaluations.