Hey
I think i have the exact same symptoms as you are describing, and have been struggling for a year with this problem.
I actually made another thread about it.. does this sound like you?
About a year ago, I got sick with what I thought was just a bad cold. This resulted in difficulty in breathing when running, which I thought would go away. A year later, I still have a lot of difficulty breathing both in running and doing everyday tasks. It feels like someone is pressing very hard on my chest, like on my breastbone and I can't take a deep breath in. The aching sometimes extends down into my ribs. I don't have any phelgm, no wheezing, nothing like that. I can't breathe hard when I run, i can only take shallow breaths or breathe a deep gasping/sighing type breath.
I have been to the doctor on several occasions, and they have pretty much ruled out asthma, since the albuterol (red, normal inhaler) doesnt do anything for me. I also take the advair purple disk, which seems to help, but not solve the problem.
I'm extremely frustrated, because like most runners, I have a high tolerance for pain and discomfort, but this has made running truly unenjoyable for me every time I set out. I've been able to maintain some level of training and competition, managing to post some ok times, but not without cost. It's my final collegiate cross country season, and I want to run well really badly.
I also got blood results and my chest xray back today. I'm not anemic, don't have lyme's and don't have a certain autoimmune disease that they were testing for. My chest xray came out alright as well.
Is it possible to suddenly develop a food or pollen type allergy? Is it possible to suddenly develop acid reflux disease? I'm not very familiar with these things, and thus I'm exploring these options. I have a pulminary function test in about a week and a half, but in the meantime, I've started taking prilosec; I figured I would give that a try.
Also of note is that the tightness very much seems to stem from right under my breastbone. When I try to run hard and push through the trouble, an aching will also seem to spread through my entire rib cage, making my ribs tender to touch. This could just be an aching from my lungs working too hard, though.
The doctor said that if I don't have asthma, vocal cord disfunction is a possibility.
ok so i know this is months later.. but did you ever figure out what was causing your trouble? i go to the pulminologist friday