After I wokeup early morning hours, I am getting cough. I consulted doctor also but he said no problems and nothing noticed in CT scan report. I am assuming that during night or immediately after waking up before brushing, I am swallowing mouth water which is causing irritation in throat and getting cough. But why I am only getting cough and noone else getting the cough, is there any problem with my mouth water?

Thats unusual,visit General Physician for appropriate approach.and maintain balanced diet and healthy lifestyle