Skip to content

Serum or plasma concentration of total bilirubin

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

This test measures the amount of bilirubin, a yellow pigment produced when red blood cells break down. It helps assess liver function and detect conditions like jaundice or bile duct blockages.

Quick summary

["Your liver’s ability to process bilirubin and rule out potential liver or bile issues."]

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

Key facts at a glance

LOINC
43297-1
Short code
HTLV I+II p32 Ab Ser Ql
Synonyms
HTLV I+II p32 Ab Ser Ql
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 This Test Matters

Total bilirubin is a key indicator of how well your liver and bile system are working. High levels can signal problems like liver disease, gallbladder issues, or red blood cell disorders. Low levels are less commonly concerning unless related to certain medications or conditions.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the draw if your lab uses a specific method. Wear a loose shirt for easy access to your arm.

Sample Collection

A healthcare provider will insert a small needle into your vein to collect blood. You may feel a brief pinch, but it’s over quickly. If you’re nervous, let your provider know—they can offer distractions or numbing cream.

Possible Results and Next Steps

Results are usually reported in milligrams per deciliter (mg/dL). Mild elevations (e.g., 1–2 mg/dL above normal) may require further testing to identify the cause, such as liver enzymes or imaging studies.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Total bilirubin

Frequently asked questions

What does a high bilirubin level mean?
High bilirubin often points to conditions like hepatitis, cirrhosis, or blockages in the bile ducts. It can also appear in hemolytic anemia (rapid red blood cell breakdown). Your doctor may order additional tests to pinpoint the cause, such as liver function tests or ultrasound.
What if my bilirubin is low?
Low bilirubin is less common but may occur with certain medications, liver disease (if bilirubin is already low due to prior processing), or genetic conditions. Your doctor will review your medical history and other test results to understand why.
How often should I get this test?
Your doctor may recommend this test periodically if you have liver disease, hemolytic conditions, or symptoms like jaundice (yellowing skin/eyes). Follow-up timing depends on your health status and any underlying issues.
  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