BNP, or B-type natriuretic peptide, is a hormone produced by the heart's ventricles in response to increased pressure and volume. It plays a crucial role in regulating blood pressure and fluid balance in the body. Elevated levels of BNP in the blood can indicate heart failure or other cardiac conditions. Doctors often measure BNP levels through a blood test to help diagnose heart-related issues. This test is particularly useful because it provides information about the heart's function and can guide treatment decisions. Monitoring BNP levels can also help assess the effectiveness of heart failure treatments.