What this marker measures
BNP and NT-proBNP measure different fragments of the same precursor; labs use one or the other (with different reference ranges). Both are used to diagnose, monitor, and guide treatment in heart failure.
High or low: what it can mean
High BNP
Elevated BNP suggests the heart may be under increased strain. It is most commonly raised in heart failure but can also be elevated with pulmonary embolism, kidney disease, or other conditions causing cardiac stress. The degree of elevation correlates with severity.
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Low BNP
Normal BNP makes significant heart failure unlikely in someone presenting with breathlessness, and is often used to rule out heart failure as a cause of symptoms.
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Frequently asked questions
What is BNP?
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BNP (and its precursor NT-proBNP) is released by heart ventricles when they are under increased stretch or stress, such as from heart failure. It is a key diagnostic and monitoring marker for heart failure.
What does BNP measure?
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BNP and NT-proBNP measure different fragments of the same precursor; labs use one or the other (with different reference ranges). Both are used to diagnose, monitor, and guide treatment in heart failure.
What does high BNP mean?
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Elevated BNP suggests the heart may be under increased strain. It is most commonly raised in heart failure but can also be elevated with pulmonary embolism, kidney disease, or other conditions causing cardiac stress. The degree of elevation correlates with severity.
What does low BNP mean?
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Normal BNP makes significant heart failure unlikely in someone presenting with breathlessness, and is often used to rule out heart failure as a cause of symptoms.
Related biomarkers
Editorial note
LabTestly explains lab markers using plain-English educational content. Reference ranges may vary by laboratory and should be interpreted with a clinician.
Educational content · Editorially reviewed for clarity · Last updated
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Not medical advice
This page is for general understanding only and does not replace medical advice from your clinician. Reference ranges can vary by laboratory, age, sex, pregnancy status, medications, and clinical context.