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B-type Natriuretic Peptide (BNP) in Blood

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

This test measures the level of B-type natriuretic peptide (BNP), a hormone produced by the heart’s ventricles in response to pressure overload or heart strain.

Quick summary

["BNP helps assess heart function and detect conditions like heart failure or fluid overload."]

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

Key facts at a glance

LOINC
42637-9
Short code
BNP Bld-mCnc
Synonyms
BNP Bld-mCnc
Category
coagulation
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Ref low
0
Ref high
100
Critical range
— – 500 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
83880
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?

Your doctor may order a BNP test to evaluate symptoms such as shortness of breath, swelling, or fatigue that could indicate heart problems. It’s also used to monitor heart function in patients with known heart conditions or those recovering from a heart attack.

What to Expect During the Test

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

How Results Are Interpreted

Results are compared to your symptoms and medical history. Elevated BNP levels may suggest conditions like heart failure, while lower levels might indicate normal heart function or other underlying issues.

Common Conditions Monitored

BNP is often used to diagnose or monitor heart failure, fluid overload, or conditions affecting heart pressure, such as pulmonary edema or cardiomyopathy.

Reference range

Normal: <100 pg/mLN/A

Specimen: whole-blood

No special preparation required. Inform provider of any chest pain or symptoms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: BNP Levels and Heart Health

Short name

BNP Blood Test

Frequently asked questions

What factors might affect my BNP test results?
Several factors can influence BNP levels, including recent exercise, dehydration, or certain medications (like diuretics). It’s important to inform your doctor about any recent changes in activity, fluid intake, or medications.
How soon will I get my results?
Results are typically available within 1–3 business days, depending on your lab. Your doctor will discuss them with you during your follow-up visit.
Can I take anything before the test?
No special preparation is needed, but avoid heavy meals or strenuous activity 24 hours before the test if instructed 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 17, 2026. · Read our editorial policy