BNP (B-type natriuretic peptide) test is a simple blood test that enables doctors to diagnose complex cardiac problems. BNP is a protein hormone which is produced at the ventricles or the lower chambers of the heart. BNP along with ANP (Atrial Natriuretic Peptide) causes blood vessels to dilate. They curb the hormones which narrow blood vessels, boost heart rate and consequently reduce the heart’s workload. Measurement of the amount of BNP helps doctors to diagnose primarily heart failure and also recent heart attacks and kidney failures too. Symptoms such shortness of breath, excessive wheezing or coughing, unexplained pain in the chest, edema (excess fluid accumulation in legs and ankles) and swelling of the abdomen in the chest warrant a BNP test.