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Bilirubin, Serum — Mass Concentration

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

A blood test that measures bilirubin, a yellow pigment produced as the liver processes hemoglobin and breaks down old red blood cells.

Quick summary

["The bilirubin test helps evaluate liver function and may be abnormal when red blood cells are being destroyed more quickly than usual."]

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

Key facts at a glance

LOINC
14423-8
Short code
Bilirub Snv-mCnc
Synonyms
Bilirub Snv-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 the blood. Bilirubin is a yellow pigment formed during the breakdown of hemoglobin, the oxygen-carrying protein in red blood cells.

Why might I need this test?

Your clinician may order this test as part of a liver panel or to investigate jaundice, which is yellowing of the skin or eyes. It can also help assess liver function and identify increased red blood cell breakdown.

How is the test performed?

A blood sample is collected, and the laboratory measures the bilirubin concentration. Bilirubin may be reported as a total measurement or evaluated along with direct and indirect bilirubin, depending on the ordered test.

How do I prepare for the test?

Fasting is usually not required for a bilirubin test unless your clinician specifically requests it. Tell your clinician about medicines, supplements, recent intense exercise, and any liver or gallbladder conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Serum bilirubin

Frequently asked questions

What does bilirubin measure?
It measures a pigment produced when the liver processes hemoglobin and old red blood cells are broken down.
What does an abnormal bilirubin result mean?
A high result may be associated with liver disease, impaired bile flow, or increased red blood cell breakdown. The result must be interpreted alongside the rest of your evaluation.
Do I need to fast before this test?
Usually not. Follow your clinician's instructions, particularly if the bilirubin test is being ordered with other tests that may require 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