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Direct Bilirubin, Serum/Plasma — Mass Concentration

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

Measures direct bilirubin in blood. Direct bilirubin is mainly the form that has been processed by the liver and is helpful in evaluating liver function and jaundice.

Quick summary

["Direct bilirubin measures bilirubin that has been processed by the liver and may help evaluate jaundice or liver problems."]

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

Key facts at a glance

LOINC
35191-6
Short code
Bilirub Direct SerPl-msCnc
Synonyms
Bilirub Direct 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 blood test measures direct bilirubin, a form of bilirubin that has been processed by the liver. It is often reported along with total bilirubin and indirect bilirubin.

Why might I need this test?

Your healthcare professional may order this test to help evaluate jaundice, liver disease, or blockage of bile flow. It can also help interpret the results of other liver function tests.

How is the test performed?

A blood sample is collected from a vein and sent to a laboratory for analysis. The test may be performed using a sample of serum or plasma, depending on the laboratory method.

How do I prepare for the test?

Usually, no special preparation is required. Follow your healthcare professional's instructions, and tell the laboratory if you are pregnant or taking medicines that may affect liver function, if applicable.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

An elevated direct bilirubin level may occur with liver inflammation or damage, impaired bile flow, or conditions affecting bile ducts. It can also be associated with jaundice, which may cause yellowing of the skin or eyes. Results should be interpreted with total bilirubin, indirect bilirubin, and the rest of your liver function tests.

Short name

Direct Bilirubin

Frequently asked questions

What is the difference between direct and indirect bilirubin?
Direct bilirubin is bilirubin that has been processed by the liver and is ready to be excreted in bile. Indirect bilirubin is the unprocessed form that circulates in the blood before the liver changes it.
Does a high direct bilirubin result always mean I have liver disease?
No. A high result can result from several conditions, including liver problems or blocked bile flow, and it should be interpreted alongside your symptoms and other laboratory results.
Is this the same as a liver function test?
Direct bilirubin is one component used to assess liver function and jaundice. It is often ordered with other tests such as total bilirubin, ALT, AST, alkaline phosphatase, and albumin.
  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