BNP and NT-proBNP

These are tests that help diagnose the presence and severity of heart failure. They may be done if you are being treated for heart failure. They may be done if you have symptoms of heart failure including:

  • Shortness of breath.

  • Fatigue.

These tests measure the concentration of BNP or NT-proBNP in the blood. Your heart releases them as a natural response to heart failure. Heart failure occurs:

  • When your heart is not strong enough to pump enough oxygen-rich blood and nutrients to meet your body's needs (hypotension).

  • When the heart itself does not get enough oxygen. This happens with angina and heart attack.

  • When the left ventricle has been stretched too much from the accumulation of blood and fluid.

Both BNP and NT-proBNP are produced mainly in the heart's main pumping chamber (left ventricle).


A blood sample is obtained by inserting a needle into a vein in the arm.


  • ANP 22-77 pg/mL or 22-77 ng/L (SI units)

  • BNP less than 100 pg/mL

  • CNP: yet to be determined

Ranges for normal findings may vary among different laboratories and hospitals. You should always check with your doctor 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 and discuss the importance and meaning of your results. They will also discuss treatment options and the need for additional tests if necessary.


Not all test results are available during your visit. If your test results are not back during the visit, make an appointment with your caregiver to find out the results. Do not assume everything is normal if you have not heard from your caregiver or the medical facility. It is important for you to follow up on all of your test results.