I had a cough from past 3-4 yrs. Sometimes I get small hair in my cough. Coughing occurs when I go outside house in dust.but it also occurs continue in home coughing with a little bulgum always. I had seen to many times to doctors but mostly they do x ray for T.B and tell me nothing serious there and give me simple medicine for cough. But this things comes back soon again. this don't Stop. What should I do and what kind of test or what type of doctor to visit regarding this??