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Total Bilirubin (Serum)

Published: August 9, 2026Updated: August 17, 2026

This test measures the amount of bilirubin in your blood, a yellow pigment produced when your body breaks down old red blood cells. It helps assess liver function and bile flow.

Quick summary

["Bilirubin levels can indicate liver or bile duct issues and how well your body processes red blood cells."]

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

Key facts at a glance

LOINC
102626-9
Short code
Tetramin IgE RAST
Synonyms
Tetramin IgE RAST
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
10
Ref high
40
Critical range
— – 500 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
rast
CPT
84484
SNOMED
302774002
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 Bilirubin Does in Your Body

Bilirubin is created when your liver and spleen remove old red blood cells from your circulation. Normally, it’s processed by the liver into a form that can be safely excreted in bile. Elevated levels may suggest problems like liver disease, gallbladder issues, or hemolytic anemia.

Why It Matters in Your Health

High bilirubin can cause jaundice (yellowing of skin/eyes) or other symptoms like dark urine or pale stools. Low levels may not indicate a problem unless related to red blood cell disorders.

Common Causes of Abnormal Results

Elevated bilirubin can stem from liver diseases (e.g., hepatitis), blockages in the bile ducts, or conditions that destroy red blood cells faster than the liver can process them.

How the Test Works

A small blood sample is taken and analyzed to measure bilirubin concentration using a chemical method that detects its presence and quantity.

Reference range

Adult: 10-40 U/LN/A

Specimen: serum

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Bilirubin

Frequently asked questions

Why might my doctor order this test?
Your doctor may request this test if you have symptoms like jaundice, unexplained fatigue, or liver-related concerns, or as part of routine checks for conditions like hemolytic anemia or liver disease.
What do my results mean?
Results outside normal ranges may signal liver or bile duct problems, but interpretation depends on your symptoms and overall health. Your doctor will discuss findings with you.
How can I prepare for this test?
No special preparation is needed. You may eat and drink normally before the test, but inform your doctor about any medications you’re taking, as they could affect 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 17, 2026. · Read our editorial policy