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Direct Bilirubin, Fluid — Substance Concentration

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

Measures direct bilirubin in a fluid specimen, usually blood serum or plasma, to help evaluate liver function and bile handling.

Quick summary

["Direct bilirubin helps assess how the liver processes and excretes bilirubin."]

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

Key facts at a glance

LOINC
25564-6
Short code
Bilirub Direct Fld-sCnc
Synonyms
Bilirub Direct Fld-sCnc
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 direct bilirubin in a fluid specimen. Direct bilirubin is the form of bilirubin that has been processed by the liver and is ready for excretion in bile.

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 provide information about liver function and the movement of bile through the body.

How is the test performed?

A blood sample is usually collected and separated into serum or plasma. A laboratory instrument then measures the amount of direct bilirubin in the fluid.

How do I prepare for the test?

Fasting is often not required, but follow any instructions from your clinician. Tell the laboratory if you are pregnant or have recently had surgery, as these factors can affect bilirubin results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Direct bilirubin

Frequently asked questions

What is the difference between direct and total bilirubin?
Direct bilirubin is bilirubin that has been processed by the liver for excretion in bile. Total bilirubin includes both direct and indirect forms.
Does a high direct bilirubin level always mean the liver is damaged?
No. It can result from several conditions, including impaired bile flow, medication effects, or liver inflammation, so it is interpreted alongside other tests.
Is this the same test as a bilirubin blood count?
No. A bilirubin blood count is generally a broader liver-related test panel, while this test specifically measures the direct form of bilirubin.
  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