i am a 28 male i am not a heavy smoker ( 5-10 sticks per day ) . my case started 4 weeks ago with a dry cough (that comes during the day only no cough when i sleep ) i go and see the doctor , he examine my lungs (using stethoscope) and he said lungs are okay your cough is due to GERD . he ask me to take prospan syrup and gastric medicine ( i dont believe i have GERD because never felt that acid comes to my throat that often ) . after one week i went to see a lung specialist she said also the same lungs are okay using stethoscope and she gave me another cough syrup . i took cough medicine but that didnt make me feel any better , later on after 3 weeks . i got a nasal congestion and blocked ear and when i bend i feel a fluid is moving in my head and i feel like it is a Sinus infection with a bit headache ( because my mother have it most of the time ). i took antihistamine and saline water to clean the congestion but i am not getting any better . cough now is better but i still cough during the day when i talk or go into a air conditioned area . i quit smoking 4 weeks ago . during all this duration no fever .
please advice me what to do . is it lungs cancer or sinus infection or asthma or ear infection ? or what is it ???