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Total Bilirubin (Serum)

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

This test measures the amount of bilirubin in your blood, a yellow pigment produced when red blood cells break down. High levels may indicate liver disease, gallbladder issues, or other conditions.

Quick summary

["Bilirubin helps diagnose liver and bile duct problems by checking for excess breakdown of red blood cells or liver dysfunction."]

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

Key facts at a glance

LOINC
21348-8
Short code
HTLV I+II IgG Ser Ql IA
Synonyms
HTLV I+II IgG Ser Ql IA
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
CPT
82784
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 It’s Done

Doctors order a bilirubin test to evaluate symptoms like jaundice (yellowing of skin/eyes), dark urine, or fatigue. It may also be used before surgeries, during pregnancy, or if you have a history of liver disease.

What to Expect

A blood sample is taken from your arm. You may feel slight discomfort, but it usually takes a few minutes. No special preparation is needed unless instructed otherwise.

What the Results Mean

Bilirubin is divided into indirect (unconjugated) and direct (conjugated) forms. High indirect bilirubin often signals hemolytic anemia (red blood cell destruction), while high direct bilirubin suggests liver or bile duct issues.

Common Causes

Elevated bilirubin can result from liver diseases (e.g., hepatitis), blockages in the bile ducts, or conditions like hemolytic anemia. Low levels are less common but may occur with certain medications or liver disorders.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Bilirubin Level

Frequently asked questions

What triggers a bilirubin test?
Symptoms like jaundice, dark urine, pale stools, or unexplained fatigue often prompt a bilirubin test. Doctors may also order it for routine check-ups, before surgeries, or if you have a family history of liver disease.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab. Follow-up with your healthcare provider if you have questions about your specific results.
Can diet affect bilirubin levels?
Dietary changes alone won’t alter bilirubin levels, but certain foods (e.g., high-fiber or fatty foods) may affect bile flow indirectly. Avoid alcohol or medications that may impact liver function before testing if advised by your doctor.
  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