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Bilirubin — Mass Concentration

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

Measures the concentration of bilirubin in a blood sample and is commonly used to evaluate jaundice, liver function, and the breakdown of red blood cells.

Quick summary

["Abnormally high bilirubin may reflect liver disease, impaired bile flow, or increased red blood cell breakdown."]

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

Key facts at a glance

LOINC
1972-9
Short code
Bilirub Amn-mCnc
Synonyms
Bilirub Amn-mCnc
Category
liver
Sample
fluid
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
2-5 mL
Stability
Room temperature: 2h, Refrigerated: 24h
Hemolysis max
300
TAT
4–24 hours
Order
routine

What is this test?

This test measures the amount of bilirubin in a blood sample. Bilirubin is a yellow pigment made when the body breaks down hemoglobin from old red blood cells.

Why might I need this test?

Your clinician may order this test to investigate yellowing of the skin or eyes, evaluate liver function, or assess conditions that cause rapid red blood cell breakdown. It is often included with a broader liver panel.

How is the test performed?

A blood sample is collected and analyzed in the laboratory to determine the bilirubin concentration. If needed, the laboratory may also calculate the amount of bilirubin that is not bound to a protein.

How do I prepare for the test?

Fasting is usually not required for a bilirubin test unless your clinician specifically requests it. Tell the healthcare professional drawing your blood about any medicines or supplements you are taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Bilirubin test

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 tests.
Does jaundice always mean my liver is damaged?
No. Jaundice can result from several causes, including liver problems, blocked bile ducts, and increased red blood cell breakdown. Bilirubin testing helps evaluate these possibilities but does not identify the cause by itself.
Do I need to fast before this test?
Usually not. Follow any fasting instructions from your clinician, particularly if the bilirubin test is part of a larger panel or another test requires fasting.
  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