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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 the 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
49928-5
Short code
WBC # DiafP
Synonyms
WBC # DiafP
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
4.5
Ref high
11
Critical range
2 N/A – 30 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
85004
SNOMED
900000000000003002
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 Bilirubin?

Bilirubin is a byproduct of red blood cell breakdown. Normally, your liver removes it from the blood and excretes it into bile, which travels to the intestines. Too much bilirubin can cause jaundice (yellowing of the skin and eyes).

Why Is This Test Done?

Doctors may order this test to check for liver problems, such as hepatitis, cirrhosis, or blockages in the bile ducts. It can also help diagnose conditions like hemolytic anemia (where red blood cells break down too quickly).

How Is the Test Performed?

A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where it is analyzed to measure bilirubin levels.

What Are Common Results?

Results are not provided with specific numeric ranges here, as they vary by lab and individual health. Your doctor will interpret the results in relation to your symptoms and medical history.

Reference range

Adult: 4.5-11.0 x 10^9/LN/A

Specimen: serum

No special preparation required. Stay well hydrated.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Total Bilirubin

Frequently asked questions

How long does it take to get results from this test?
Results are typically available within 1 to 3 business days, depending on your lab’s processing time. Follow-up with your healthcare provider to discuss findings.
Can diet affect bilirubin levels?
Dietary changes alone won’t alter bilirubin levels, but certain foods (like excessive alcohol or fatty foods) may influence liver function indirectly. Avoiding alcohol and eating a balanced diet can support liver health.
What if my bilirubin is high?
High bilirubin may indicate liver disease, bile duct issues, or red blood cell disorders. Your doctor will guide further testing or treatments based on the cause, such as medications or lifestyle adjustments.
  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