Bilirubin
A breakdown product of red blood cells processed by the liver.
What is it
Bilirubin is produced from the breakdown of red blood cells and processed by the liver for excretion. Total bilirubin includes both direct (conjugated) and indirect (unconjugated) forms.
Why it's measured
Elevated bilirubin has been associated with liver dysfunction, bile flow obstruction, and increased red blood cell breakdown in published research.
Reference range
Standard laboratory reference
0.2 – 1.2 mg/dL
Reference ranges vary by laboratory. Your individual reference range will appear on your test report and should be interpreted by your physician in the context of your overall health profile.
What results may indicate
Elevated
Has been associated with liver and bile duct conditions, hemolysis, and Gilbert's syndrome in research literature.
Lower
Is generally not clinically concerning.
These associations are general. They are not a personal diagnosis or prediction. Discuss your individual results with your physician in the context of your full health profile.
When it's measured
Part of standard liver panels.
Related markers
Measured in
A complete look at your heart, hormones, metabolism, inflammation, and longevity systems — drawn at Quest or LabCorp, reviewed by a U.S.-licensed physician.
Explore the Apex Panel →This information is for general educational purposes only and is not medical advice. Lab results alone are not intended to diagnose, treat, or cure any condition and do not replace the advice of a healthcare provider. OPTML does not offer medical advice, a diagnosis, medical treatment, or any form of medical opinion.