B-Type Natriuretic Peptide (BNP) is a hormone produced by the heart ventricles in response to increased pressure and volume overload. This test measures BNP levels in the blood to diagnose and monitor congestive heart failure (CHF). BNP acts as a natural diuretic and vasodilator, helping to reduce blood pressure and fluid retention. Elevated BNP levels indicate increased ventricular pressure and are strongly associated with heart failure severity. The test is particularly valuable for distinguishing between cardiac and non-cardiac causes of shortness of breath in emergency settings, as BNP levels above 80-100 pg/mL strongly suggest heart failure. BNP measurements help guide treatment decisions, monitor response to heart failure therapy, and assess prognosis. The test is also useful for evaluating participants with suspected heart failure who present with non-specific symptoms, providing objective evidence to support clinical assessment.