DefinitionBrain natriutetic peptide (BNP) test is a blood test that measures levels of a protein made by your heart and blood vessels. This protein is called BNP. BNP levels are higher than normal when you have heart failure.How the test is performedA blood sample is needed. For information on how this is done, see: VenipunctureThis test is usually done in the emergency room or hospital. Results take up to 15 minutes. In some hospitals, a finger prick test with rapid results is available.How the test will feelWhen the needle is inserted to draw blood, you may feel moderate pain, though most people feel only a prick or a stinging sensation. Afterward there may be some throbbing or bruising.Why the test is performedYour doctor may order this test if you have signs of heart failure. Symptoms include shortness of breath and swelling of your legs or abdomen. The test helps your doctor make sure the problems are due to your heart and not your lungs, kidneys, or liver.It is unclear if repeated BNP tests are helpful in guiding treatment in those already diagnosed with heart failure.Normal ValuesIn general, results less than 100pg/mL are a sign of heart failure.The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.What abnormal results meanBNP levels go up when the heart cannot pump the way it should.A result greater than 100 pg/mL is abnormal. The higher the number, the more likely heart failure is present and the more severe it is.What the risks areThere is very little risk involved with having your blood taken. Veins and arteries vary in size from one patient to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.Other risks associated with having blood drawn are slight but may include:Excessive bleedingFainting or feeling light-headedHematoma (blood accumulating under the skin)Infection (a slight risk any time the skin is broken)Special considerationsA related test, called the N-terminal pro-BNP test, is done in the same way. It provides similar information to your health care provider.ReferencesRedfield MM. Heart Failure with normal ejection fraction. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 30.Jessup M, Abraham WT, Casey DE, Feldman AM, Francis GS, Ganiats TG, et al. 2009 focused update: ACCF/AHA Guidelines for the Diagnosis and Management of Heart Failure in Adults: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines: developed in collaboration with the International Society for Heart and Lung Transplantation. Circulation. 2009 Apr 14;119(14):1977-2016.Lindenfeld J, Albert NM, Boehmer JP, et al. Executive Summary: HFSA 2010 Comprehensive Heart Failure Practice Guideline. J Card Fail 2010;16:475e539.Reviewed ByReview Date: 10/13/2011David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc., and Michael A. Chen, MD, PhD, Assistant Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, Washington.