Hi @falconfly,
Brain natriuretic peptide, also called B-type natriuretic peptide (BNP), is a protein that your heart and blood vessels produce. BNP helps your body eliminate fluids, relaxes blood vessels and funnels sodium into your urine. The test helps in diagnosing and monitoring congestive heart failure.

@rwhite1919 and @philippe had mentioned BNP or B-type natriuretic peptide in previous posts; I hope they return with some more information for you. According to Mayo Clinic, "A high level of BNP alone isn't enough to diagnose a heart problem. Your doctor will also consider your risk factors and other blood test results." https://www.mayoclinic.org/diseases-conditions/heart-disease/in-depth/heart-disease/art-20049357
Here are some additional details, including reference values:
– https://www.mayomedicallaboratories.com/test-catalog/Clinical+and+Interpretive/83873

@falconfly, I hope this helps, and I'd sincerely appreciate it if you are able to post a follow-up and we can continue the conversation - wish you all the best for tomorrow.