Bilirubin (Total)

What is Bilirubin (Total)?

Bilirubin is a yellow-orange pigment produced from the breakdown of heme in aged red blood cells. The spleen breaks down hemoglobin into unconjugated (indirect) bilirubin, which the liver then conjugates (direct bilirubin) for excretion in bile. Total bilirubin is the sum of both fractions.

What might a high or low Bilirubin (Total) mean?

Elevated bilirubin causes jaundice (yellowing of skin and eyes). The pattern of direct vs. indirect elevation helps localize the problem: high indirect suggests hemolysis or Gilbert's syndrome; high direct suggests liver disease or bile duct obstruction. Mildly elevated bilirubin in Gilbert's syndrome is actually associated with cardiovascular protection due to bilirubin's antioxidant properties.

What is the typical reference range for Bilirubin (Total)?

The general-population reference range shown here is 5 – 21 umol/L. Reference ranges describe the general population and are not a personal target — discuss your results with your physician.

What can affect Bilirubin (Total)?

It may be higher with: Gilbert's syndrome (benign, affects 5-10% of population), Hemolytic anemia (increased RBC breakdown), Liver disease (hepatitis, cirrhosis), Bile duct obstruction (gallstones, tumors), Medications (rifampin, atazanavir), Fasting (transiently raises unconjugated), Neonatal jaundice, Strenuous exercise. It may be lower with: Treatment of underlying cause, UV light therapy (neonatal), Phenobarbital (induces conjugation enzymes).