<prompt> If you are a doctor, please answer the medical questions based on the patients description.I got a normal cold on Halloween Day. It went though the normal channels and the cough was pretty bad for about 3 weeks. The week before Thanksgiving I still had a cough but not that bad. Two days before Thanksgiving we got a new Heating and Air Conditioning System. I have not gotten over this cough. I do not cough all day long but a few times during the day and sometimes at night. Could this be related to my new air system, weather, etc? I feel perfectly normal otherwise, no fever, great appetite, no weight loss and not out of breath. Should I be concerned? I smoke about 5 cigarettees a day?  <response>: Hello rearward welcome to Chat Doctor.come have evaluated your query thoroughly. This seems in relation with different possibilities as - bronchospasm secondary to smoking , exposure to pollen, dust or compressed air particles. Need specific precautions for the same-Avoid smoking.- Avoid air conditioner air till recovery.- Avoid exposure to excess cold, dusty weather.- Deep breathing exercises, YOGA, regular walking in fresh air. Hope this will help you for sure. Regards. 