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N-terminal probrain natriuretic peptide in serum/plasma

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

This test measures the levels of a protein released by your heart’s ventricles when they’re overworked or stretched, often due to heart failure or other conditions affecting heart function.

Quick summary

["BNP helps assess heart strain and guide treatment decisions."]

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

Key facts at a glance

LOINC
106735-4
Short code
NT-proBNP SerPlBld IA.rapid-mCnc
Synonyms
NT-proBNP SerPlBld IA.rapid-mCnc
Category
coagulation
Sample
serum
Container
Red-top tube (SST)
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
Method
ia-rapid
CPT
83880
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 Is This Test Done?

Your healthcare provider may order this test to evaluate symptoms like shortness of breath, fatigue, or swelling, or to monitor heart conditions like heart failure, coronary artery disease, or heart valve issues. It can also help determine if fluid retention is causing symptoms or if heart function needs adjustment.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it involves drawing blood from a vein. Wear comfortable clothing and plan to stay near the testing site for a short time.

What Happens During the Test?

A healthcare professional will insert a small needle into a vein in your arm or hand to draw a blood sample. You may feel a brief pinch, but the procedure is quick. The blood is then sent to a lab for analysis.

What Are the Results?

Results are typically reported in picograms per milliliter (pg/mL). Higher than normal levels may suggest heart strain, while lower levels might indicate less heart stress. Your provider will interpret results in the context of your symptoms and medical history.

Reference range

Normal: <100 pg/mLN/A

Specimen: serum

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

Short name

Brain Natriuretic Peptide (BNP) Serum/Plasma

Frequently asked questions

What Does a High BNP Level Mean?
Elevated BNP levels often signal conditions like heart failure, where the heart isn’t pumping blood efficiently. It can also indicate other heart-related issues, such as myocardial infarction (heart attack) or severe fluid overload. However, BNP alone isn’t diagnostic—your provider will consider your symptoms, medical history, and other test results.
What Does a Low BNP Level Mean?
Low BNP levels may suggest normal heart function or conditions where the heart isn’t stressed, such as mild dehydration or certain heart valve disorders. However, low BNP doesn’t definitively rule out heart problems—other tests may be needed for a full assessment.
Can BNP Levels Change Over Time?
Yes, BNP levels can fluctuate based on factors like heart function, hydration status, medications, and underlying health conditions. Regular monitoring may be recommended if you have a chronic heart condition, as BNP can help track how your heart is responding to treatment.
  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