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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 liver process waste products.

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
41821-0
Short code
Deprecated Tib-L XR
Synonyms
Deprecated Tib-L XR
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
xr
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

Your doctor may order this test to check for liver diseases, such as hepatitis, cirrhosis, or bile duct blockages. It can also help diagnose conditions like Gilbert’s syndrome or hemolytic anemia, where red blood cells break down more quickly than usual.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm to draw blood. If you’re nervous, let your healthcare provider know so they can help make it more comfortable.

What the Results Mean

Higher than normal levels may suggest liver problems, jaundice (yellowing of skin/eyes), or other conditions affecting red blood cell breakdown. Lower levels are less commonly significant but could indicate certain genetic or metabolic disorders.

Common Causes of Abnormal Results

Elevated bilirubin can result from liver disease, blocked bile ducts, or increased red blood cell destruction. Low levels are rare but may occur in rare genetic conditions or severe liver disease.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Total Bilirubin

Frequently asked questions

Could my bilirubin levels be affected by what I eat?
Dietary factors like fatty foods or certain medications (e.g., antibiotics) may temporarily influence liver function, but they rarely cause long-term changes in bilirubin levels. Always discuss any concerns with your doctor.
Will I need to take any medications before this test?
No medications are typically required beforehand, but if you’re on blood thinners or liver-related medications, let your provider know to avoid potential interactions.
Is there a difference between total bilirubin and direct/indirect bilirubin?
Yes, total bilirubin combines direct (processed by the liver) and indirect (unprocessed) forms. Your doctor may order both tests separately to pinpoint the cause of changes in your results.
  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