Since he thinks it is anxiety, can you elaborate on any of his reasoning for such a diagnosis? You feel you have a breathing issue but did doc agree and what did he say specifically?
The question would be, how thorough was your doctor's exam? Was he a specialist or a general doc? I would think that anyone experiencing shortness of breath would at least for caution's sake be sent to a heart and lung specialist just to make sure nothing is going on. I'd also ask, do you experience chronic anxious thoughts? Anxiety isn't just physiological symptoms, it is most noted by obsessively anxious thinking. Do you do that? If not, it's not likely to be anxiety. We pretty much know when we're feeling really anxious. Anxiety is sometimes accompanied by physiological symptoms and sometimes it isn't. Sometimes anxiety is caused by a physiological problem rather the other way around. So you do need to eliminate the possibility of something being wrong physically even if you are suffering anxiety. Which brings me full circle back to the original question: how thorough of an exam did your doc give you? Have you frequently complained of problems you didn't turn out to have?
When I stand up initially all the blood goes to my legs and I can brown out for a moment, so I've learned to stand up slowly.
The other thing that can happen to me is if my pulse goes high,) above 120, then I've read the heart actually pumps less blood, and I actually get shortness of breath. -- I purchased a finger pulse measuring device for about $20 I reall, and now if I get shortness of breath I take my pulse with it. (I suppose I could just take my pulse the old fashioned way.) I've learned from experimenting that I can lower my pulse by holding my breath. I have no idea why that works, sometimes at least.