Hello and welcome to ask a doctor service. I read your query and here is my answer. You said you have cough from 5 years, is it productive or dry? If productive, does it contain blood and how is its colour? Do you smoke? Do you have shortness of breath or any heart disease like hypertention etc? At what time of the day or night you cough? Do you run fever? Of you have dry cough which is most of the time at night then it is because of GERD. IF IT IS productive along with fever then it may be due to lung infection. If you do smoke then you may have chronic bronchitis if it is productive as well. If you have dry cough along with shortness of breath then you may have interstitial lung disease. Need a proper history and examination. You need to consult your primary doctor or pulmonologist. Hope i answered your question. Feel free to ask more if you need further assistance before contacting your doctor. Thanks.