BNP / NT-proBNP
B-type Natriuretic Peptide
What this test measures
BNP and NT-proBNP are hormones released by your heart when it's under strain. They're used to help diagnose heart failure and monitor how well treatment is working.
Understanding the numbers
Typical range: BNP: <100 pg/mL | NT-proBNP: <300 pg/mL (varies by age)
Levels increase with age. Higher cut-offs are used for older adults. Different labs may use different tests.
- Normal / unlikely HF: 0–400 pg/mL (NT-proBNP)
- Raised — 6-week echo: 400–2000 pg/mL (NT-proBNP)
- Highly suggestive — 2-week echo: 2000–4000 pg/mL (NT-proBNP)
Key numbers
- 400 pg/mL (NT-proBNP) — Above = referral for echocardiogram within 6 weeks
- 2000 pg/mL (NT-proBNP) — Above = urgent echocardiogram within 2 weeks
NICE NG106 chronic heart failure: NT-proBNP <400 ng/L makes heart failure unlikely; 400-2000 ng/L refer for echocardiogram within 6 weeks; >2000 ng/L urgent echo within 2 weeks. Values are lower for BNP. Age, sex, kidney function and obesity all affect the interpretation.
Ranges can vary slightly between laboratories — your report may show slightly different numbers. This page does not read or interpret your result; your GP looks at it alongside your history and other tests.
What a higher-than-normal result can mean
- May indicate your heart is under strain (possible heart failure)
- The higher the level, the more likely heart failure is present
- Can also be raised by kidney disease, lung disease, or anaemia
- Atrial fibrillation and other heart conditions can raise levels
Questions you could ask your GP
- Does this result suggest heart failure?
- Do I need an echocardiogram (heart scan)?
- What might be causing my symptoms if not heart failure?
- How can I look after my heart health?
Example stories
These are made-up examples to show how results are talked about in real appointments. They are not real patients.
Breathlessness — BNP rules out heart failure
Geraldine had been breathless on exertion for three months. NT-proBNP 180. Chest X-ray was normal.
What the GP said: “Your NT-proBNP is low — heart failure is very unlikely to be the cause. We'll explore other causes — anaemia, lung disease, or deconditioning — and plan a gentle exercise programme.”
What happened next: Spirometry showed mild COPD; pulmonary rehab helped.
A low BNP or NT-proBNP is very reassuring — it effectively rules out heart failure in primary care. Breathlessness has many other causes worth exploring.
Breathless — intermediate NT-proBNP
Sonia had breathlessness and leg swelling. NT-proBNP was 1200.
What the GP said: “Your NT-proBNP is clearly raised — this supports heart failure. I'll refer you for an echocardiogram within six weeks. In the meantime, we can start a diuretic for symptom relief.”
What happened next: Echocardiogram showed HFpEF (preserved ejection fraction). Sonia was started on an SGLT2 inhibitor and diuretic.
An NT-proBNP of 400-2000 ng/L triggers a 6-week echo pathway. Starting symptom treatment while awaiting imaging is reasonable — early treatment with diuretics and HF medications improves quality of life.
Very high NT-proBNP — urgent referral
Terence had worsening breathlessness and orthopnoea. NT-proBNP 3800. Known hypertension and Type 2 diabetes.
What the GP said: “This is highly suggestive of significant heart failure. I'm arranging an urgent echo within two weeks and starting a loop diuretic now.”
What happened next: Echo showed reduced ejection fraction (35%). HF medicines (ACE inhibitor, beta-blocker, SGLT2 inhibitor, MRA) were started sequentially.
NT-proBNP >2000 ng/L needs urgent echo and treatment — these patients have significant heart failure and benefit most from guideline-directed therapy.
Raised NT-proBNP in AF without heart failure
Vikrant had atrial fibrillation, no breathlessness. NT-proBNP 620 on a routine check.
What the GP said: “NT-proBNP often rises in AF even without heart failure. Echocardiogram is still worthwhile to check heart structure, but at your level we don't assume HF without clinical features.”
What happened next: Echo showed normal structure; no heart failure. AF was managed with a rate-control and anticoagulation plan.
NT-proBNP is raised by many non-HF factors: AF, kidney disease, advanced age, anaemia. Use it alongside symptoms and echocardiogram — not in isolation.
Before you act on anything here
This page is general information, written to help you understand — it is not personal medical advice and it cannot tell you what is right for you. Talk to your own GP, pharmacist or nurse about your own health.
- Need help now but it's not an emergency? Call NHS 111 or use 111.nhs.uk.
- Emergency? Call 999 or go to A&E.