I get this symptom when standing and walking. As I'm standing up I get a tightening and heavy sensation in my diaphragm. It impairs my breathing some what. I can't really take in a full deep breath becuase of the tightness and there is no weezing with this problem. As long as I walk and stand I have it, but soon as I sit it goes away totally. Some days the tightness isn't noticable others it bothers me the entire time I'm on my feet. And other days the sensation fades away after being up for a few minutes. I have told various doctors about this over the last 2 yrs that I have had POTS. With not much more reaching then a raised eyebrow and a hmmm. My neurologist finally said that I could be having some type of spasms causing my diapragm to tighten. Thats pretty much what I told her! She dismissed it as being unimportant and told me to do yoga and meditation to calm my nerves and strengthen my diapragm. I told this to another doctor a couple of years ago when my POTS started and he said it could be blood pooling in that area. This problem isn't getting worse and it isn't going away. Just real bothersome on top of all the stuff. I was just curious if anybody else has to deal with this. Does anbody else have this particular problem, any insights or ideas????