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Serum or plasma concentration of total bilirubin

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

This test measures the total amount of bilirubin in your blood, a yellow pigment produced when red blood cells break down. It helps assess liver function and detect conditions like jaundice or bile duct blockages.

Quick summary

["A bilirubin test helps diagnose liver or bile problems and monitor conditions like jaundice."]

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

Key facts at a glance

LOINC
5402-3
Short code
VZV Ab Titr Ser LA
Synonyms
VZV Ab Titr Ser LA
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
la
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

Why This Test Matters

Bilirubin is normally processed by your liver and excreted through bile. If your liver isn’t working well, bilirubin can build up in your blood, leading to yellowing of the skin or eyes (jaundice). High levels may signal liver disease, gallbladder issues, or other health concerns.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the test if it’s part of a liver function panel. Bring any medications you’re taking, as some may affect results.

How the Test Works

A blood sample is drawn from a vein, usually in your arm. The sample is sent to a lab where bilirubin levels are measured using a colorimetric method that detects its presence in serum or plasma.

Possible Causes of Abnormal Results

High bilirubin levels may result from liver diseases (like hepatitis), bile duct obstructions, hemolytic anemia (rapid red blood cell breakdown), or certain medications. Low levels are less common but may occur with severe liver damage or certain genetic conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Total Bilirubin

Frequently asked questions

What does a high bilirubin level mean?
A high bilirubin level often indicates a problem with liver function, bile flow, or red blood cell breakdown. Your doctor may recommend further tests to identify the cause, such as imaging studies or additional blood work.
What does a low bilirubin level mean?
Low bilirubin levels are less common and may suggest severe liver disease, though they can also occur in newborns during the first few days of life (physiologic jaundice). Always discuss results with your healthcare provider.
How often should I get this test?
Your doctor will determine how often to check bilirubin levels based on your health history, symptoms, or specific medical conditions. Regular monitoring may be needed if you have liver disease, a history of jaundice, or other risk factors.
  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