Skip to content

Direct Bilirubin, Serum/Plasma — Mass Concentration

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

Measures direct bilirubin in serum or plasma to help evaluate liver function and the causes of jaundice.

Quick summary

["Direct bilirubin helps assess liver function and possible causes of yellowing of the skin or eyes."]

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

Key facts at a glance

LOINC
1968-7
Short code
Bilirub Direct SerPl-mCnc
Synonyms
Bilirub Direct SerPl-mCnc
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 and is ready for removal from the body. It is commonly used with total bilirubin and indirect bilirubin to help evaluate jaundice and liver function.

Why might I need this test?

Your clinician may order this test if you have yellowing of the skin or eyes, dark urine, pale stools, itching, or symptoms that suggest a liver or bile duct problem. It may also be used to monitor people with known liver disease or to help interpret a total bilirubin result.

How is the test performed?

A blood sample is collected from a vein and tested in a laboratory. The laboratory uses an approved method to measure the amount of direct bilirubin in the serum or plasma.

How do I prepare for the test?

Fasting is usually not required for this test, but follow your clinician's or laboratory's instructions. Tell the healthcare team if you are pregnant or may be pregnant, because some laboratory methods can interfere with the result.

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 indirect bilirubin?
Direct bilirubin has been processed by the liver, while indirect bilirubin has not yet been processed. Measuring both can help clinicians determine whether an abnormal bilirubin result is more likely related to liver dysfunction or increased blood cell breakdown.
Does a high direct bilirubin result always mean I have liver disease?
No. It can occur with liver disease, bile duct blockage, certain medications, or other conditions. Your clinician will interpret the result with your symptoms and other test findings.
Do I need to fast before this test?
Fasting is generally not required, but specific laboratory instructions may vary. Follow the directions provided by your healthcare professional or testing laboratory.
  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