What does an elevated bnp mean?

Maybe CHF. An elevated bnp may be assoc. W/ chf. Symptoms of CHF include increasing shortness of breath, especially when one lies down at night which is relieved by sitting up; rapid weight gain (ex: >1-2 lbs in 24 hrs), leg swelling, fatigue. See your doc if you have these symptoms.
BNP:Natriuretic Pept. :blood natriuretic peptide. This is a substance hormone-like created in the heart that gets elevated in congestive heart failure and during heart attacks. It is used in conjunction with the clinical signs to monitor pts with congestive heart failure. Higher-than-normal results suggest that a person is in heart failure, and the level of bnp or nt-probnp in the blood is related to the severity.