B-type natriuretic peptide (BNP) is a hormone produced by the heart, specifically in the ventricles, in response to increased pressure and volume. It plays a crucial role in regulating blood pressure and fluid balance by promoting the excretion of sodium and water through the kidneys. BNP levels are often measured in clinical settings to help diagnose and manage heart failure. Elevated BNP levels indicate that the heart is under stress, providing valuable information for healthcare providers in assessing a patient's condition and determining appropriate treatment options.