Natriuretic Peptide Tests (BNP, NT-proBNP)

Natriuretic peptides are proteins that your heart and blood vessels make. Natriuretic peptide tests measure the amount of these proteins in a sample of your blood. They are mainly used to help confirm or rule out heart failure in people who have symptoms.

Heart failure is also called congestive heart failure. If you have this condition, your heart has trouble pumping enough oxygen-rich blood to meet your body's needs. Two types of natriuretic peptides can be measured to check for possible heart failure.

Your health care provider will decide which of these peptides to test: Brain natriuretic peptide (BNP) is a protein that's a type of hormone. A hormone is a chemical messenger in your bloodstream that controls the actions of certain cells or organs. BNP has 'brain' in its name because that's where researchers first discovered it.

Your heart makes and releases BNP into your bloodstream when it's working harder than normal to pump blood. The BNP tells your blood vessels to open wider and your kidneys to get rid of water and salt through urine (pee). This helps reduce the workload on your heart by lowering blood pressure and reducing the amount of blood your heart has to pump. ; N-terminal pro b-type natriuretic peptide (NT-proBNP) is a protein that's an 'ingredient' for making the BNP hormone.

Like BNP, your heart makes larger amounts of NT-proBNP when it has to work harder to pump blood.; It's normal to have some BNP and NT-proBNP in your bloodstream. But higher than normal levels for your age and sex may be a sign of heart failure.

Why this test is done

You may need a BNP test or an NT-proBNP test if you have symptoms that could mean you have heart failure. These include:

• Feeling short of breath
• Swelling in your abdomen (belly), feet, legs, and/or veins in your neck
• Fatigue and/or general weakness
• Coughing
• Inability to sleep lying flat
• Needing to urinate (pee) a lot, especially at night
• Loss of appetite and nausea

If you have already been diagnosed with heart failure, your provider may order one of these tests to learn more about your condition.

How to prepare

You don't need any special preparations for a BNP test or an NT-proBNP test.

Sample type

Blood

Other names for this test

brain natriuretic peptide, NT-pro B-type natriuretic peptide test, B-type natriuretic peptide, N terminal proBNP