Natriuretic peptides

Brain natriuretic peptide is a protein the heart and blood vessels make. It's also called B-type natriuretic peptide (BNP). BNP helps the body get rid of fluids, relaxes blood vessels and moves sodium into the urine.

With heart damage, the body puts high levels of BNP into the blood to try to ease the strain on the heart. One important use of BNP is to try to learn whether shortness of breath is due to heart failure.

BNP levels vary by age, gender and weight. For people who have heart failure, getting a baseline BNP can be helpful. Future tests might help measure how well treatment works.