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Bilirubin — Mass Concentration

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of bilirubin in a blood sample. It can help evaluate liver function and the breakdown of red blood cells.

Quick summary

["Abnormally high bilirubin may reflect liver disease, increased blood-cell breakdown, or bile duct obstruction."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
49763-6
Short code
Bilirub Pcar-mCnc
Synonyms
Bilirub Pcar-mCnc
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

Bilirubin is a yellow pigment made when the body breaks down old red blood cells. This test measures the amount of bilirubin in the sample, often as part of a liver function or blood-work panel.

Why might I need this test?

Your clinician may order this test to investigate jaundice, liver disease, bile duct problems, or excessive red blood cell breakdown. It may also be used to monitor treatment or the course of an existing condition.

How is the test performed?

A blood sample is collected and analyzed in the laboratory. The result is reported as a bilirubin concentration, and it may be listed as total, direct, or indirect bilirubin depending on the test ordered.

How do I prepare for the test?

Fasting is usually not required, but follow any instructions from your clinician. Tell the laboratory if you have recently had hemolysis, a blood transfusion, liver disease, or taken medicines that may affect the result.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Bilirubin

Frequently asked questions

What does a high bilirubin level mean?
It may indicate that the liver is not processing bilirubin normally, that bile flow is obstructed, or that red blood cells are breaking down faster than usual. Your clinician will interpret the result with your symptoms and other test results.
Why are total, direct, and indirect bilirubin different?
Total bilirubin includes all bilirubin in the blood. Direct bilirubin is the form that has been processed by the liver, while indirect bilirubin generally reflects bilirubin produced by red blood cell breakdown.
Do I need to fast before this test?
Fasting is usually unnecessary, although special instructions may apply to a broader laboratory panel. Confirm the preparation requirements with the healthcare professional who ordered the test.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy