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Bilirubin, Total (Serum or Plasma)

Published: August 9, 2026Updated: August 17, 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

["Your liver’s health and red blood cell breakdown can be checked with this simple blood test."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
97769-4
Short code
nRBC # BldCo
Synonyms
nRBC # BldCo
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Ref low
4.2
Ref high
5.9
Critical range
2 N/A – 7 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
85041
SNOMED
900000000000003001
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 Is This Test Done?

Doctors may order a total bilirubin test to diagnose or monitor conditions affecting your liver, bile ducts, or red blood cells. High levels can signal liver disease, blockages, or hemolysis (red blood cell destruction), while low levels may indicate certain liver or bile duct problems.

What to Expect Before the Test

No special preparation is needed, but avoid eating or drinking for 8–12 hours before the test if instructed. Bring your medical history and any medications to your appointment.

How the Test Works

A blood sample is taken from a vein in your arm. The sample is sent to a lab, where bilirubin levels are measured using a chemical reaction that detects its presence.

Possible Results and Their Meaning

Results are compared to standard ranges, but individual ranges can vary. Elevated levels may require further testing to identify the cause, such as liver disease, gallstones, or hemolytic anemia.

Reference range

Adult males: 4.2-5.9; Females: 3.8-5.1 x 10^12/LN/A

Specimen: whole-blood

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

What does a high bilirubin level mean?
High bilirubin levels often indicate liver or bile duct issues (e.g., hepatitis, cirrhosis, or blockages) or conditions that cause red blood cells to break down too quickly (e.g., anemia). Your doctor will discuss next steps based on your symptoms and test results.
What does a low bilirubin level mean?
Low bilirubin levels are less common but may suggest liver or bile duct problems (e.g., bile duct obstruction) or certain genetic conditions. Further testing may be needed to explore underlying causes.
Can diet affect bilirubin levels?
Diet alone rarely affects bilirubin levels, but certain foods (e.g., high-fiber or cruciferous vegetables) may interact with liver function indirectly. Always follow your doctor’s advice regarding test preparation.
  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 17, 2026. · Read our editorial policy