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Total Bilirubin (Serum)

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

This test measures the total amount of bilirubin in your blood. Bilirubin is a yellow pigment produced when red blood cells break down, and it helps your body remove waste.

Quick summary

["Bilirubin helps identify liver function and bile flow issues."]

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

Key facts at a glance

LOINC
40948-2
Short code
Y entero O:3 Ab CSF Ql
Synonyms
Y entero O:3 Ab CSF Ql
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why This Test Matters

Your doctor may order this test to check for liver problems, such as hepatitis, gallbladder disease, or bile duct blockages. It can also help diagnose conditions like jaundice, where the skin or eyes turn yellow due to high bilirubin levels.

How the Test Works

A small blood sample is taken from your arm. The bilirubin in your blood is measured using a chemical reaction that detects its presence, often through a color change that is read by a machine.

What to Expect Before the Test

No special preparation is needed for this test. You can eat and drink normally on the day of the test. If you are on blood thinners, let your doctor know before the test.

What to Expect During the Test

The test involves a quick, painless blood draw from a vein in your arm. You may feel a slight pinch, but it usually takes only a few minutes to complete.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

High levels of bilirubin can indicate liver disease, bile duct problems, or conditions that cause red blood cells to break down too quickly. Low levels are less common but may suggest certain liver or bile duct issues that need further evaluation. Consistent monitoring of bilirubin levels can help track the effectiveness of treatments for liver conditions.

Short name

Total Bilirubin

Frequently asked questions

What does a high bilirubin level mean?
A high bilirubin level often suggests problems with your liver or bile ducts, such as obstruction, inflammation, or disease. This can lead to jaundice, where your skin or eyes appear yellow. Your doctor may recommend further tests to determine the exact cause.
What does a low bilirubin level mean?
Low bilirubin levels are less common and may indicate certain liver or bile duct conditions that need further investigation. It can sometimes be associated with conditions affecting red blood cell production or liver function.
How often should I get this test?
Your doctor will determine how often you need this test based on your health condition, symptoms, and medical history. Regular monitoring may be necessary if you have liver disease, a history of jaundice, or other related conditions.
  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