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Total Bilirubin (Mass Concentration in Serum)

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. Bilirubin is normally processed by the liver and excreted in bile.

Quick summary

["Bilirubin helps your liver remove waste and keeps your skin and eyes from turning yellow if levels are too high."]

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

Key facts at a glance

LOINC
3025-4
Short code
T4 Bld-mCnc
Synonyms
T4 Bld-mCnc
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Ref low
4.5
Ref high
12
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
84436
SNOMED
302345006
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why It’s Done

Your doctor may order a total bilirubin test if you have symptoms like jaundice (yellowing of skin or eyes), dark urine, pale stools, or if they suspect liver, bile duct, or gallbladder problems. It can also be part of routine check-ups for conditions like hemolytic anemia or liver disease.

What to Expect

A small blood sample is taken from a vein, usually in your arm. You may feel a slight pinch, but it’s quick. No special preparation is needed unless instructed otherwise.

What the Results Mean

Bilirubin levels above normal can indicate issues like liver disease, blocked bile ducts, or red blood cell disorders. However, results alone don’t diagnose a condition—they guide further testing.

Common Causes of Abnormal Results

High bilirubin levels may be due to liver problems (like hepatitis), blocked bile flow, or rapid red blood cell destruction. Low levels are less common but could relate to liver disease or certain medications.

Reference range

Adult: 4.5-12.0 μg/dLN/A

Specimen: whole-blood

Take your thyroid medication after the blood draw if applicable. No fasting required.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Total Bilirubin

Frequently asked questions

What does my bilirubin level tell me about my health?
A bilirubin test helps identify potential liver or bile system issues. Elevated levels may signal jaundice, liver inflammation, or blockages. Your doctor will discuss results in the context of your symptoms and medical history.
How often should I get this test?
Frequency depends on your health. Routine adults may not need it unless they have risk factors (e.g., liver disease, hemolytic anemia). Follow your doctor’s advice for monitoring.
Can I eat or drink before this test?
No special diet is needed, but avoid alcohol or heavy meals 24 hours before if instructed. Hydration is fine unless your doctor specifies otherwise.
  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