I found myself becoming short of breath the other day when I leaned back in a chair to watch a film. The same thing happened again today when I laid back on my bed to chat on the phone. I suddenly feel like I'm not taking in enough air, my head gets pins and needles/headache pain and I become slightly dizzy and tired. If I stand up or even slightly move forwards, it all goes away again.
This is very scary, especially because it never happens when I'm walking around, leaning forwards etc, but only when I lean back, meaning I can't relax. Any idea what could do this to me? I do have a lot of mucus in my throat and some trouble swallowing, if that contributes?