@nycmom Back when the SOB first started back on 2012, I also did the best I could to resist taking a deep breath. This, combined with breathing exercises and only breathing through my nose, made the SOB go away for a good year. But for whatever reason it came back. So I think CO2 levels has something to do with it and for whatever reason, breathing gets out of sorts. Mine has been present consistently for a couple of years, but this time it persists no matter what I do, though I have been able to manage it to a tolerable level using breathing exercises. But I'm going to try to resist taking a deep breath as much as I can and maybe over time I'll get out of the habit of taking deep breaths even when I don't really need to.