Am unable to take deep breathes as I feel something blocking the trachea with pain in chest region near sternum, however I have done 2 pft tests in the past and 2 chest x rays, all normal, I had also done hrct thorax which shows no abnormality except- few subcentimetric lymph nodes on pre tracheal and pre cranial regions, which doctors say as normal. I have also done echo and ecg and all are normal, I feel as if it is due to something pressing on the wind pipe or maybe due to chest not expanding properly. Yesterday on doing dips exercise in tbe gym for a few minutes it felt as the block is removed upon stretching however it came back. What should be done now? I have taken 1.) q mont tab for 2 months 2.) predmet - which gave me relief for one day but the problem was back again 3.) pantop 40 for 7 days.