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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, and is commonly used to evaluate jaundice and liver function.

Quick summary

["Abnormal bilirubin levels can help identify problems with red blood cell breakdown, the liver, or bile drainage."]

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

Key facts at a glance

LOINC
35194-0
Short code
Bilirub SerPl-msCnc
Synonyms
Bilirub SerPl-msCnc
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 your blood. Bilirubin is a yellow pigment made during the normal breakdown of red blood cells. The liver processes bilirubin so it can be removed from the body.

Why might I need this test?

Your clinician may order this test to help evaluate jaundice, which may cause yellowing of the skin or eyes. It can also provide information about liver function, bile duct drainage, or the rate of red blood cell breakdown.

How is the test performed?

A blood sample is collected from a vein and sent to a laboratory. The laboratory measures the bilirubin concentration in the serum or plasma using a standardized testing method.

How do I prepare for the test?

This test usually requires no special preparation. If it is part of a broader liver panel or another test that requires fasting, follow the specific instructions provided by your healthcare professional.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

A higher bilirubin level may occur with increased red blood cell breakdown, liver inflammation or damage, or impaired bile flow. Results must be interpreted with other tests and your symptoms because an isolated elevation does not identify one specific condition.

Short name

Bilirubin

Frequently asked questions

What does a high bilirubin level mean?
It may indicate that red blood cells are being broken down faster than usual, that the liver is not processing bilirubin normally, or that bile flow is obstructed. Your clinician will interpret the result alongside your medical history and other laboratory tests.
Does this test require fasting?
Usually, no. Fasting may be required only if bilirubin is being checked as part of another panel with specific preparation instructions.
Is bilirubin the same as a liver function test?
Bilirubin is one component used to assess liver-related function, but a complete liver panel usually includes several additional measurements.
  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