Natriuretic Peptide Tests (BNP, NT-proBNP)
Natriuretic peptides are proteins that your heart and blood vessels make.
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. Other names: brain natriuretic peptide, NT-pro B-type natriuretic peptide test, B-type natriuretic peptide, N terminal proBNP
Why is this test ordered? 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.
Clinical Interpretation
The meaning of your test results will depend on your age, sex, medical history, family history, and the results of other tests. Ask your provider to explain what the results of your BNP or NT-proBNP test say about your health and how this information may affect your treatment. A BNP or NT-proBNP test alone can't diagnose the cause of your symptoms. But in general, if you have symptoms that could be caused by heart failure: Normal results on a BNP or NT-proBNP usually mean that you're unlikely to have heart failure. Your provider may order other tests to find out what's causing your symptoms. If you have obesity , your weight may affect the accuracy of your test results, making your levels lower than they really are. If your provider suspects heart failure, you may have other heart health tests even if your BNP or NT-proBNP levels are normal. Higher than normal levels of BNP or NT-proBNP mean that you could have heart failure. Your provider will probably order other heart health tests to help make a final diagnosis. In most cases, the higher the level of your test results, the more serious your heart failure may be. But other health conditions can increase BNP and NT-proBNP levels. That's why your medical history is important for understanding whether high test results mean you have heart failure. Other conditions that can cause high levels of BNP and NT-proBNP include: Kidney failure Other types of heart disease , including conditions that affect your heart valve s or heart muscle Certain lung disorders , including a blood clot in your lung ( pulmonary embolism ) and high blood pressure in your lungs ( pulmonary hypertension ) If you have questions about your results, talk with your provider. Learn more about laboratory tests, reference ranges, and understanding results
Clinical Protocol & Patient Advice
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You don't need any special preparations for a BNP test or an NT-proBNP test.
Usage Guidance
- Reference ranges vary by laboratory. Always discuss your specific results with a qualified healthcare professional.
Source: MedlinePlus, National Library of Medicine. View the original.