Whenever I lift some bag on my back or do some other physical work , sometimes I start having difficult breathing. My back feels like it's being pushed inside and my chest is popping out from front and it becomes difficult to sleep. I have difficult breathing without any cough or fever. It then heels itself after 2 days. Is this disease ? Or can this be ignored ? Even if I am wearing some heavy jacket , this problem may happen. I have no chronic problem . Only my stomach bulges due to overeating. Otherwise no problem.