BNP Test (B-type Natriuretic Peptide): Results And More - Healthline

Có thể bạn quan tâm

HealthlineSubscribeExplore more in Heart Failure

What is it used for?

A BNP test detects a rise in BNP, which indicates heart failure. Your doctor may recommend this test if you have symptoms of heart failure, such as shortness of breath.

Early diagnosis of heart failure can ensure that you get quick and effective treatment to prevent further complications.

Your doctor may order a BNP blood test if you have symptoms of heart failure, including:

trouble breathing (dyspnea)
feeling exhausted or weak for no apparent reason
rapid weight gain without a change in diet or activity
inability to concentrate or remain alert
abnormally high or irregular heart rate
coughing a lot and producing white or pink phlegm
nausea or having no appetite

A BNP test can also help rule out heart failure. Other conditions can cause elevated BNP levels, including lung or kidney conditions and obesity.

How to prepare for the test

No special preparation is needed for a BNP test. As it is possible for stress and anxiety to temporarily raise your BNP levels, just do your best to stay calm during the blood draw.

If you faint at the sight of blood or feel weak from fasting, your doctor may recommend that someone come with you in case you’re not able to drive or get yourself home.

How is this test performed?

A BNP test is done by drawing blood from a vein in your arm using a hypodermic needle. This process is known as venipuncture.

A machine then measures levels of BNP or another heart hormone, called N-terminal-pro BNP (NT-pro-BNP), in the blood sample.

The results from the test are usually ready in 15 to 20 minutes. Results may take up to a week if the blood is sent to a separate lab facility for analysis.

BNP blood test results explained

Your results will indicate if your BNP levels are high enough to suspect a diagnosis of heart failure. If you already have a diagnosis of heart failure, the results can help your doctor find out whether heart failure treatments are working.

Generally, BNP levels below 100 picograms per milliliter (pg/mL) are considered normal. But normal BNP levels may vary depending on your age and sex.

Normal BNP range by age and sex

BNP levels increase naturally as you age, and people assigned female at birth typically have slightly higher levels. Underlying conditions can raise your BNP levels, too. Regardless of age or gender, a BNP level of 100 pg/mL or less is considered normal. The higher your level goes above that, the higher your chances are of developing heart failure. Other conditions, like kidney disease, can increase these chances even more.

Your doctor may use BNP tests alongside other diagnostic tests to confirm if you have heart failure or if other conditions are responsible for the increase in your BNP levels.

The chart below shows the normal range, as well as the cutoff levels for a heart failure diagnosis at different ages. These figures use data from a specific type of BNP test called the N-terminal (NT)-pro hormone BNP (NT-proBNP).

Age Range	BNP Level	What It Means
All ages	Under 100 pg/mL	Normal
Ages 50 and older	450 pg/mL and up	Acute heart failure
Ages 50 to 75	900 pg/mL and up	Acute heart failure
Ages 75 and older	1,800 pg/mL and up	Acute heart failure

What do high or low BNP levels mean?

In most cases, a high BNP is the greater cause for concern. As your BNP level increases above 100 pg/mL, your chances of developing heart failure increase. These changes already increase with age, so early increases in your BNP level could be cause for alarm.

Generally, anything over 100 pg/mL can indicate some level of heart failure. Heart failure is graded in terms of your ejection fraction or the amount of blood your heart pumps out with every beat. The ejection fraction is a rough estimate of how well your heart is functioning. For example, an EF of 50% to 70% is normal, and this means that your heart is functioning at about 50% to 70% of its potential. It’s possible to have heart failure with a normal EF, but in many cases, your heart’s overall function will decrease as your heart failure worsens.

In acute heart failure, your heart function is severely limited — to the point where even regular daily activities like cooking and bathing can be a strain. Depending on your age, a BNP result of 400 pg/mL to 1,800 pg/mL signals acute heart failure.

While a high BNP level is more well-known for being worrisome, some studies suggest that a low BNP can also be a sign of heart trouble. In one study, a small portion of people hospitalized for conditions like heart failure, abnormal heart structure or function, and abnormal hemodynamics (heart rate, blood pressure, and similar readings) had lower than normal BNP levels. Some were so low, in fact, that they couldn’t even be detected on lab tests.

How accurate is a BNP test?

This test has a 98% success rate in ruling out heart failure as a cause of increased BNP levels.

Exercise may cause BNP levels to rise temporarily. Stress can raise your levels of the hormone cortisol, which can also temporarily increase BNP levels.

To confirm a heart failure diagnosis, your doctor may also recommend the following tests:

full physical examination
complete blood count (CBC) blood test
chest X-ray
echocardiogram
electrocardiogram (EKG)
cardiac catheterization
cardiac MRI

Are there any risks to a BNP test?

There are no serious risks to having a BNP test performed. Like most tests performed by venipuncture, drawing blood from your vein could cause symptoms like:

soreness
bruising
bleeding
lightheadedness

These symptoms are usually short-lived, if they develop at all. If you’re concerned about getting lightheaded, you may want to make sure someone drives you home afterward.

If you have symptoms of heart problems like shortness of breath or chest pain, not having a BNP test performed may pose greater risks than the test itself. Early detection of heart failure can help you get treatment sooner and may improve your overall prognosis.

How can I lower my BNP levels?

Improving your heart health can help reduce the effects of heart failure and other heart conditions. Consider these heart-healthy steps:

If you smoke, talk with your doctor about setting up a quit plan.
Stop consuming alcohol altogether, or drink fewer alcoholic beverages.
If you are overweight or have obesity, work with your doctor to create a sustainable weight management plan.
Manage stress through practices such as yoga or meditation.
Exercise more often than not. Aim for at least 150 minutes of exercise a week.
Get 7-9 hours of sleep a night.

Depending on the cause of your heart failure and other conditions, your doctor may recommend the following:

a CPAP machine if you have sleep apnea and aren’t breathing well at night
reducing the use of NSAIDs for pain
managing conditions like high blood pressure and diabetes
medications for heart failure, such as ACE inhibitors or beta-blockers
diuretics to help pass more fluid out of your body
surgery for coronary bypass or heart valve repair
inserting a pacemaker

What are the next steps?

If high BNP levels indicate heart failure, your doctor will tell you the steps to take to prevent complications of this condition.

See your doctor regularly to monitor your BNP levels if needed, and follow any instructions to maintain your best heart health.

Are BNP tests covered by Medicare?

In general, most blood tests ordered by your doctor as medically necessary to diagnose or treat a condition are usually covered by Medicare. In the case of BNP testing, this testing is covered, but with some restrictions. The test may not be covered as a stand-alone test or as a tool for monitoring congestive heart failure. Additionally, Medicare will usually only cover up to four BNP tests each year.

Frequently asked questions

Can a complete blood count (CBC) detect congestive heart failure?

A CBC blood test can reveal abnormal levels of certain white blood cells and immune cells, which can suggest problems with your heart.

What are the four signs your heart is quietly failing?

The four signs of heart failure are unexplained breathlessness, fatigue, fainting, and swelling in the ankles or legs.

However, these symptoms can be caused by other things, and some people with heart failure can experience other symptoms, such as a cough, for example.

That said, getting medical attention is crucial to rule out heart failure, as it is life threatening.

What is the blood marker for a heart attack?

When you have a heart attack, a protein called troponin is released into your blood. This protein is normally found in the heart muscle, so finding it in a lab result can help diagnose a heart attack.

Takeaway

BNP is a blood test that is used to help diagnose conditions like heart failure. This test is commonly done in the emergency department if you show up with symptoms like shortness of breath.

High BNP levels are usually associated with an increased risk of developing heart failure, but low BNP levels can also signal some heart problems.

If your doctor orders a BNP test for you, they will interpret your results based on your individual age, gender, and other health conditions.

How we reviewed this article:

SourcesHistoryHealthline has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical journals and associations. We only use quality, credible sources to ensure content accuracy and integrity. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.

American Heart Association. (2017.) Ejection fraction heart failure measurement.https://www.heart.org/en/health-topics/heart-failure/diagnosing-heart-failure/ejection-fraction-heart-failure-measurement
Bachmann KN, et al. (2021.) Unexpectedly low natriuretic peptide levels in patients with heart failure.https://www.jacc.org/doi/abs/10.1016/j.jchf.2020.10.008
BNP and NT-proBNP. (2021).https://labtestsonline.org/tests/bnp-and-nt-probnp
Brain natriuretic peptide test. (2022).https://medlineplus.gov/ency/article/007509.htm#:~:text=BNP%20levels%20go%20up%20when,can%20cause%20high%20BNP%20levels.
B-type natriuretic peptide (BNP) testing. (2021).https://www.cms.gov/medicare-coverage-database/view/lcd.aspx?lcdid=34410&ver=37
Harvard Health Publishing. (2019.) BNP: An important new cardiac test.https://www.health.harvard.edu/newsletter_article/bnp-an-important-new-cardiac-test
Heart failure. (2022).https://www.nhs.uk/conditions/heart-failure/
Hill SA, et al. (2014.) Use of BNP and NT-proBNP for the diagnosis of heart failure in the emergency department: a systematic review of the evidence. https://link.springer.com/article/10.1007/s10741-014-9447-6
Fe White M, et al. (2014). Self-care guide for the heart failure patient.https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.113.003991
Troponin test. (n.d.).https://medlineplus.gov/lab-tests/troponin-test/

Share this article

Medically reviewed by Darragh O'Carroll, MD — Written by Tim Jewell and Rachael Zimlich, RN, BSN — Updated on February 6, 2024

Health Conditions

Condition Spotlight

Wellness Topics

Product Reviews

Featured Programs

Featured

Lessons

Newsletters

Lifestyle Quizzes

Health News

This Just In

Top Reads

Video Series

Find Your Bezzy Community

Follow us on social media

Related Topics

Symptoms

Related Articles

Diagnosis

Related Articles

Types

Related Articles

Treatment

Related Articles

Prognosis

Related Articles

Stages

Related Articles

Related Conditions

Related Articles

Complications

Related Articles

Management

Related Articles

Diet

Related Articles

Causes & Risk Factors

Related Articles

Surgery

Related Articles

What is it used for?

How to prepare for the test

How is this test performed?

BNP blood test results explained

Normal BNP range by age and sex

What do high or low BNP levels mean?

How accurate is a BNP test?

Are there any risks to a BNP test?

How can I lower my BNP levels?

What are the next steps?

Are BNP tests covered by Medicare?

Frequently asked questions

Can a complete blood count (CBC) detect congestive heart failure?

What are the four signs your heart is quietly failing?

What is the blood marker for a heart attack?

Takeaway

How we reviewed this article:

related stories

Read this next

Liên Hệ