hello for about 4 weeks I have felt breathlessness. I am normally quite a fit person I do taekwondo and at times its tiring, but this is different, I feel that I am not getting enough air and that something is trapped in my throat and chest, at first I thought it might be a mild chest infection, because I have suffered with them before on a few occasions but they have been bad where it felt someone was sat on my chest. but this is different and now it feels like I have trapped air in throat and wanting to burp, its really a second opinion as I have seen doctor twice and had a blood test today. I am 48 and I wondered at first if it was thyroid connected. can you help.