Blood Test

BNP & NT-proBNP (Heart Failure Test)

Name: BNP and NT-proBNP Test: Normal Range | HealthReview
Creator: Suman Konda
Published: 2026-07-05

BNP and NT-proBNP are hormones released by the heart when it is under stress or pressure. They are the definitive blood tests for diagnosing and monitoring heart failure.

Written and clinically reviewed by Suman Konda, PharmD, Clinical Pharmacist · Based on peer-reviewed sources · Editorial policy · Not medical advice

Last reviewed and updated: 01 August 2026 · How we check our content

What are BNP and NT-proBNP?

B-type natriuretic peptide (BNP) and its inactive fragment NT-proBNP are hormones released by the ventricular walls of the heart when they are stretched or under increased pressure: as happens in heart failure, when the heart cannot pump blood efficiently and fluid backs up. Both tests indicate the same process; different labs use different assays. They are the most important blood tests for: diagnosing heart failure in a patient with shortness of breath, assessing severity, monitoring treatment response, and predicting prognosis.

Normal range and interpretation

Test	Normal	Grey Zone	Heart Failure Likely
BNP	< 100 pg/mL	100 – 400 pg/mL	> 400 pg/mL
NT-proBNP (<75 yrs)	< 125 pg/mL	125 – 900 pg/mL	> 900 pg/mL
NT-proBNP (≥75 yrs)	< 125 pg/mL	:	> 1,800 pg/mL

HIGH BNP / NT-proBNP: Heart Failure or Cardiac Stress

Very high BNP or NT-proBNP strongly indicates heart failure. In patients with shortness of breath, a high BNP is more than 90% accurate at confirming a cardiac cause. Very high values (>1,000 pg/mL BNP or >5,000 pg/mL NT-proBNP) indicate severe heart failure and poor short-term prognosis without treatment. BNP/NT-proBNP also rises in: acute coronary syndrome, pulmonary embolism, atrial fibrillation, severe kidney disease (reduced clearance) and critical illness.

LOW / NORMAL BNP / NT-proBNP: Heart Failure Unlikely

A normal BNP or NT-proBNP in a patient with shortness of breath is very reassuring that heart failure is NOT the cause. The negative predictive value exceeds 95%. This helps redirect investigation toward lung causes (asthma, COPD, pneumonia, pulmonary embolism) or non-cardiac causes.

Using BNP to monitor heart failure treatment

In a patient already diagnosed with heart failure, serial BNP or NT-proBNP measurements track response to treatment. A falling BNP as medications (ACE inhibitors, ARBs, beta-blockers, diuretics, SGLT2 inhibitors) are optimised indicates improving cardiac function. A rising BNP during apparent stability warns of decompensation before hospitalisation becomes necessary.

Questions to ask your doctor

Is my shortness of breath from my heart or my lungs?
What is my BNP trend over time?
Do I need an echocardiogram?
How well is my heart failure treatment working?
What medications protect my heart and reduce my BNP?

Frequently asked questions

Does the trend matter more than one BNP & NT-proBNP reading?

For long-term monitoring it generally does. A figure that has drifted across several tests says more than a single measurement, and a stable result sitting slightly outside the range is often simply that person's baseline.

Do BNP & NT-proBNP results from two different laboratories compare directly?

Not reliably. Methods differ, so a change between labs can reflect the assay rather than a change in you. Where BNP & NT-proBNP is being tracked over time, staying with one laboratory makes the comparison meaningful.

How soon should BNP & NT-proBNP be rechecked after an abnormal result?

It depends on how abnormal the value was and why it was ordered, from days for a markedly abnormal result to months for routine monitoring. If no interval was given, that is worth asking rather than assuming.

References

The clinical information on this page is drawn from peer-reviewed sources indexed by the US National Library of Medicine. Links go to the source so you can read it yourself.

Natriuretic Peptide B Type Test. In: StatPearls. Treasure Island (FL): StatPearls Publishing. NCBI Bookshelf NBK556136