Wow, this thread is making me feel validated. I too have similar symptoms . Starting maybe 20 years ago or more I remember having shortness of breath . I did see a pulmonologist and cardiologist and ruled many things but out. I ran marathons and functioned fine but had bouts of SOB. I am now suffering my worst boot by far. Three weeks ago I was in the ER for shortness of breath as well as pain when I breathed in. Negative chest X Ray and bloodwork was normal. Ruled out blood clot. I saw a cardiologist who was confident it was not heart related . Normal EKG. He said at some point we can do stress test but didn’t feel it was urgent . Same with echo. Last night I woke up in near panic because I couldn’t breathe. I practiced closed mouth breathing and it helped a bit. The SOB is always there though. Once I’m aware of it it gets worse. I’ve tried Ativan (just makes me care less about SOB but it doesn’t go away). I’ve tried Zantac . Nothing works . It’s not much worse with exercise . I am going through a stressful time and did notice this bout began of SOB began right after . But it doesn’t feel like it originated from anxiety though though now my anxiety is very bad as a result. It feels like a nightmare I can’t escape .