BNP, Brain Natriuretic Peptide

These tests are used to help diagnose the presence and severity of heart failure. It is done if you have symptoms of heart failure or if you are being treated for heart failure. Symptoms can include shortness of breath and fatigue. Either BNP or NT-proBNP may be ordered to help diagnose heart failure and to grade the severity of that heart failure.

There are various causes of heart failure. Currently, the condition is diagnosed by symptoms such as swelling in the legs (edema), difficulty breathing, shortness of breath, and fatigue. Diagnosis also involves chest X-rays and an ultrasound test called echocardiography. Despite this information, heart failure is still often confused with other conditions. BNP and NT-proBNP levels can help caregivers tell the difference between heart failure and other problems, such as lung disease. An accurate diagnosis is important because heart failure can be successfully managed with various medical treatments. Another reason for using BNP and NT-proBNP is to evaluate risk in people who have chest pain. It has been found that high BNP predicts an increased risk of death or subsequent heart attack in patients with acute coronary syndromes.

These tests measure the concentration of BNP or NT-proBNP in the blood. When the heart is stressed, it produces a precursor, pro-BNP. This is cleaved to release the active hormone BNP and an inactive fragment, NT-proBNP. Both BNP and NT-proBNP are produced mainly in the heart's left ventricle. This is the heart's main pumping chamber. Your heart releases them as a natural response to heart failure, low blood pressure (hypotension), a lack of oxygen to the heart, or an enlarged heart (hypertrophy).


Adults: less than 167 pg/mL (less than 167 ng/L)

Ranges for normal findings may vary among different laboratories and hospitals. You should always check with your caregiver after having lab work or other tests done to discuss the meaning of your test results and whether your values are considered within normal limits.


Your caregiver will go over the test results with you. Your caregiver will discuss the importance and meaning of your results. He or she will also discuss treatment options and additional tests, if needed.


It is your responsibility to obtain your test results. Ask the lab or department performing the test when and how you will get your results.