only cough

I am 34 years old and I have had cough since more than 4 weeks which haven't respond to any antitussive,dexamethasone.......I am used to this episode of cough that takes a long time .....there are no other symptoms.....no sputum....no fever....nothing at all......it's just only cough.and I've never smoked a cigarette..........please guide me..................thanks

[SwanSong]

I had a dry cough which lasted about two years and because I had no other symptoms for about  14 months I never asked anyone about it. Then I developed chest pain, heart palpitations and other symptoms upon exertion. Finally, the condition which was connected to my cough made itself known, pericarditis. It took months to show with all the symptoms.

I have never smoke a cigarette.