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Total Bilirubin, Blood — Concentration

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

Measures total bilirubin in a blood sample to help evaluate red blood cell breakdown, liver function, and bile flow.

Quick summary

["An elevated total bilirubin level may reflect liver disease, 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
48449-3
Short code
CT Orbit W contr IV
Synonyms
CT Orbit W contr IV
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ct
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?

Total bilirubin measures the amount of a yellow liver pigment in the blood. It reflects the balance between bilirubin production from the breakdown of red blood cells and the liver's ability to process and remove it.

Why might I need this test?

This test may be ordered as part of a liver panel or when symptoms suggest liver inflammation, bile duct obstruction, or increased red blood cell breakdown. It is also commonly used to monitor newborns or people receiving certain medications.

How is the test performed?

A blood sample is collected and analyzed in the laboratory. Depending on the laboratory's method, the total bilirubin result may be measured directly or calculated from other bilirubin measurements.

How do I prepare for the test?

Fasting is usually not required, but follow any specific instructions from your healthcare professional. Tell the laboratory about recent blood transfusions, illness, or medications, because these can affect bilirubin results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Total bilirubin

Frequently asked questions

What does a bilirubin blood test measure?
It measures the concentration of bilirubin, a yellow pigment produced when red blood cells are broken down and processed by the liver.
Do I need to fast before this test?
Fasting is usually not necessary for a bilirubin test. If it is being performed with other laboratory tests, follow the preparation instructions provided for the full panel.
What can cause an abnormal bilirubin result?
High bilirubin may result from liver disease, bile duct blockage, or increased red blood cell breakdown. Results should be interpreted with other liver tests and your healthcare professional's assessment.
  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