Brain natriuretic peptide
Peer reviewed by Dr Doug McKechnie, MRCGPLast updated by Dr Philippa Vincent, MRCGPLast updated 7 May 2025
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Professional Reference articles are designed for health professionals to use. They are written by UK doctors and based on research evidence, UK and European Guidelines. You may find the Congestive heart failure article more useful, or one of our other health articles.
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Synonym: B-type natriuretic peptide
Brain natriuretic peptide (BNP) levels increase markedly in left ventricular dysfunction and the level in heart failure correlates with symptom severity. BNP can therefore be an important clinical marker for the diagnosis of heart failure in patients with unexplained dyspnoea.
Other clinical applications, such as screening for asymptomatic ventricular dysfunction, establishing the prognosis or guiding the titration of drug therapy and prediction of future cardiovascular events, are under investigation but have not yet been sufficiently validated for widespread clinical use.1
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What is Brain natriuretic peptide?
BNP is a biologically active peptide of 32 amino acids and has vasodilator and natriuretic properties. BNP is cleaved from the 108-amino acid pro-brain natriuretic peptide released from the cardiac ventricles in response to stretching of the chamber.
The second remnant after cleavage, N-terminal pro-brain natriuretic peptide (NT-proBNP), is a 76-amino acid peptide with no known biological function which circulates at higher concentrations than BNP and may represent cardiac status over longer periods.2
The release of BNP appears to be in direct proportion to ventricular volume expansion and pressure overload. BNP increases with right or left systolic or diastolic heart failure. It is an independent predictor of high left ventricular end-diastolic pressure. BNP levels decrease after effective treatment of heart failure.
Until recently, BNP measurement was controversial as there was no clear evidence of the value of treating BNP levels, independent of symptoms.3 Recent studies have confirmed that treating BNP levels reduces morbidity and mortality.4The STRONG-HF study was stopped early due to the benefits seen in rapid up-titration of heart failure medication guided by BNP measurement.
BNP has been shown to be the single most accurate predictor of the absence of heart failure if the levels are below 100 nanomoles per litre.4
Measurement of brain natriuretic peptide
BNP is mainly used in the assessment of patients with possible heart failure. The National Institute for Health and Care Excellence (NICE) recommends:5
Measure N-terminal pro-B-type natriuretic peptide (NT-proBNP) in people with suspected heart failure.
Because very high levels of NT-proBNP carry a poor prognosis, refer people with suspected heart failure and an NT-proBNP level above 2000 ng/litre (236 pmol/litre) urgently, to have specialist assessment and transthoracic echocardiography within two weeks.
Refer people with suspected heart failure and an NT-proBNP level between 400 and 2000 ng/litre (47 to 236 pmol/litre) to have specialist assessment and transthoracic echocardiography within six weeks.
An NT-proBNP level less than 400 ng/litre (47 pmol/litre) in an untreated person makes a diagnosis of heart failure less likely. The level of serum natriuretic peptide does not differentiate between heart failure with reduced ejection fraction and heart failure with preserved ejection fraction.
Review alternative causes for symptoms of heart failure in people with NT-proBNP levels below 400 ng/litre. If there is still concern that the symptoms might be related to heart failure, discuss with a heart failure specialist.
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Potential causes of abnormal brain natriuretic peptide levels5
High levels of serum natriuretic peptides can be associated with:
Age over 70 years.
Heart failure
Left ventricular hypertrophy.
Ischaemia.
Tachycardia.
Right ventricular overload.
Hypoxaemia (including pulmonary embolism).
Renal dysfunction (eGFR less than 60 ml/minute/1.73 m2).
Reduced levels of serum natriuretic peptides can occur with:
Obesity.
African or African-Caribbean family origin.
Treatment with diuretics, angiotensin-converting enzyme (ACE) inhibitors, beta-blockers, angiotensin II receptor blockers (ARBs) or mineralocorticoid receptor antagonists (MRAs).
Further reading and references
- Ray SG; Natriuretic peptides in heart valve disease. Heart. 2006 Sep;92(9):1194-7. Epub 2005 Oct 26.
- Heart failure - chronic; NICE CKS, August 2024 (UK access only)
- Jankowski M; B-type natriuretic peptide for diagnosis and therapy. Recent Pat Cardiovasc Drug Discov. 2008 Jun;3(2):77-83.
- Hobbs FD, Davis RC, Roalfe AK, et al; Reliability of N-terminal pro-brain natriuretic peptide assay in diagnosis of heart failure: cohort study in representative and high risk community populations. BMJ. 2002 Jun 22;324(7352):1498.
- Natriuretic Peptides: Role in the Diagnosis and Management of Heart Failure: A Scientific Statement From the Heart Failure Association of the European Society of Cardiology, Heart Failure Society of America and Japanese Heart Failure Society; Journal of Cardiac Failure
- Natriuretic Peptides in Clinical Practice: A Current Review; Lee and Aw; Journal of Immunological Sciences
- Chronic heart failure in adults - diagnosis and management; NICE Guidance (Sept 2018)
- Inflammation and Circulating Natriuretic Peptide Levels; H Fish-Trotter et al
- McKechnie DG, Papacosta AO, Lennon LT, et al; Inflammatory markers and incident heart failure in older men: the role of NT-proBNP. Biomark Med. 2021 Apr;15(6):413-425. doi: 10.2217/bmm-2020-0669. Epub 2021 Mar 12.
Article history
The information on this page is written and peer reviewed by qualified clinicians.
Next review due: 6 May 2028
7 May 2025 | Latest version

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