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Bilirubin, Serum/Plasma — Mass Concentration

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

A blood test that measures bilirubin, a yellow pigment produced when the body breaks down red blood cells. It can help evaluate liver function and the causes of jaundice.

Quick summary

["Abnormal bilirubin levels may reflect liver problems, increased blood-cell breakdown, or blocked bile flow."]

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

Key facts at a glance

LOINC
109063-8
Short code
Bilirub Msmt SerPl
Synonyms
Bilirub Msmt SerPl
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?

This test measures the amount of bilirubin in serum or plasma, the liquid portion of blood. Bilirubin is a yellow pigment formed during the breakdown of red blood cells and is normally processed by the liver.

Why might I need this test?

Doctors may order this test as part of a liver panel, to investigate yellowing of the skin or eyes called jaundice, or when symptoms suggest liver disease or hemolysis, the destruction of red blood cells. It may also be used to monitor certain conditions or medicines that can affect the liver.

How is the test performed?

A healthcare professional draws blood into a collection tube. The sample is then analyzed in a laboratory, and the bilirubin result is reported as a concentration. The laboratory's testing method may vary, and the test may be ordered alone or as part of a broader liver panel.

How do I prepare for the test?

Fasting is usually not required for an isolated bilirubin test, but follow any instructions provided with a broader liver panel. Tell your healthcare professional about medicines or supplements you take and whether you are pregnant, as these factors can sometimes influence liver tests or test interpretation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Serum/Plasma 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. Other laboratory findings are needed to determine the most likely cause.
Does jaundice always mean the liver is seriously damaged?
No. Jaundice can have several causes, including a harmless inherited tendency such as Gilbert syndrome, medication effects, or more significant liver or blood-cell conditions. A clinician should interpret the result rather than relying on bilirubin alone.
Can I take medicines before this test?
Do not stop prescribed medicines unless your healthcare professional tells you to. Some medicines can affect liver function or bilirubin levels, so provide a complete list of medicines and supplements to the laboratory or ordering clinician.
  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