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Indirect Bilirubin, Serum/Plasma — Mass Concentration

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

Measures indirect bilirubin in serum or plasma to help evaluate jaundice and distinguish between increased bilirubin from blood-cell breakdown or liver disease.

Quick summary

["An elevated indirect bilirubin level may reflect increased blood-cell breakdown, reduced liver processing, or a related liver disorder."]

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

Key facts at a glance

LOINC
35192-4
Short code
Bilirub Indirect SerPl-msCnc
Synonyms
Bilirub Indirect 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?

Indirect bilirubin, also called unconjugated bilirubin, is a form of bilirubin that has not yet been processed by the liver. This test measures its amount in a blood sample and may be performed directly or calculated from related bilirubin results.

Why might I need this test?

This test is often ordered when jaundice, yellowing of the skin or eyes, or unexplained changes in liver blood tests are present. It can help evaluate whether increased bilirubin is related to blood-cell breakdown, impaired liver processing, or another condition affecting bilirubin metabolism.

How is the test performed?

A blood sample is collected by venipuncture, and the serum or plasma is analyzed in the laboratory. Depending on the laboratory method, indirect bilirubin may be measured directly or calculated from total and direct bilirubin results.

How do I prepare for the test?

No special preparation is usually required for an isolated indirect bilirubin test. If it is part of a broader liver panel, follow the preparation instructions provided for that panel, especially if you are told to fast.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Indirect bilirubin

Frequently asked questions

What is the difference between indirect and direct bilirubin?
Indirect bilirubin has not yet been processed by the liver, while direct bilirubin has been processed and is usually water-soluble. Indirect bilirubin rises in conditions involving blood-cell breakdown or reduced liver processing.
Does an elevated indirect bilirubin level always mean serious liver damage?
No. Mild elevation is common with benign conditions such as Gilbert syndrome, especially during fasting, stress, or illness. Other laboratory results and your overall health are needed to determine the cause.
Can jaundice be present with a normal bilirubin result?
Jaundice is usually visible when bilirubin is elevated, but skin color can be affected by other factors. A clinician should interpret the symptom together with the laboratory result and physical examination.
  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