NT-proBNP
Protein from the heart, measured mainly when heart failure is suspected
Also known as
Definition
NT-proBNP (N-terminal pro-B-type natriuretic peptide) is a protein formed when the body makes the hormone BNP. The heart produces more of it when it has to work harder to pump blood. A small amount in the blood is normal. The test is mainly used to help confirm or rule out heart failure in people with symptoms such as shortness of breath.
| Parameter | Value |
|---|---|
| Unit | ng/l (equivalent to pg/ml) |
| Reference Range | No single range: what counts as normal depends on age and sex, among other things. For suspected chronic heart failure, the UK guideline NICE NG106 uses 400 ng/l as a threshold for adults; below it, heart failure is less likely in untreated people. Labs may differ; the range on your own report is what counts, and your doctor puts the result into context. |
Agree on your personal target range with your doctor.
1 ng/l equals 1 pg/ml. NICE also gives its thresholds in pmol/l: 400 ng/l equals 47 pmol/l, 2,000 ng/l equals 236 pmol/l. BNP and NT-proBNP have different normal ranges; their values are not interchangeable.
↓ What a low value means
A normal value usually makes heart failure unlikely in people with symptoms such as shortness of breath; the cause of the symptoms may then be looked for elsewhere. Some factors can lower the levels: obesity, African or African-Caribbean background, and certain heart medicines such as diuretics, ACE inhibitors, ARBs, ARNIs, beta-blockers or mineralocorticoid receptor antagonists. Further tests may therefore follow despite a normal value; your doctor decides.
↑ What a high value means
A value above the usual range for age and sex can be linked to heart failure; further tests such as a heart ultrasound usually follow. In most cases, the higher the value, the more severe heart failure may be. Raised values also occur with other causes, such as kidney failure, diseases of the heart valves or heart muscle, pulmonary embolism, pulmonary hypertension, COPD, sepsis, diabetes or liver cirrhosis. The value alone is not a diagnosis; it is interpreted together with your history and other findings.
When to test
The test is mainly done for symptoms that may point to heart failure, such as shortness of breath, swelling in the belly, legs or feet, swollen neck veins, fatigue, coughing, breathlessness when lying flat or frequent urination at night. In known heart failure, the test can help assess severity and course. No special preparation is needed.
Frequently asked questions
What is the difference between BNP and NT-proBNP? +
BNP is a hormone that widens the blood vessels and makes the kidneys excrete more water and salt, which eases the workload on the heart. NT-proBNP is a by-product formed when BNP is made. Both tests provide similar information but have different normal ranges. Your doctor decides which test is measured.
Is NT-proBNP part of a routine check-up? +
Not primarily. According to MedlinePlus, the test is mainly used for symptoms that may point to heart failure, in known heart failure, and in certain cases after a heart attack or with unstable angina. A single value can only be interpreted together with your history and other findings.
Which thresholds does the NICE NG106 guideline use? +
For suspected heart failure, the UK guideline recommends specialist assessment with a heart ultrasound within 2 weeks above 2,000 ng/l and within 6 weeks at 400 to 2,000 ng/l. It links very high values to a poorer prognosis. Your doctor puts your own value into context.
What else besides heart failure can affect the value? +
With obesity, values can come out lower than they really are; certain heart medicines can also lower them. Kidney, lung or liver disease, sepsis or diabetes, on the other hand, can raise them. Do not stop any medicine on your own; tell your care team which ones you take.
NT-proBNP
Sources
- MedlinePlus, National Library of Medicine: Natriuretic Peptide Tests (BNP, NT-proBNP)
- MedlinePlus, National Library of Medicine: Brain natriuretic peptide test (Medical Encyclopedia)
- NICE, National Institute for Health and Care Excellence: Chronic heart failure in adults: diagnosis and management (NG106), Recommendations
Last updated: October 05, 2026
This information is for orientation only and does not replace medical advice. Reference ranges can vary by laboratory, method and country.