<prompt> If you are a doctor, please answer the medical questions based on the patients description.I have had a cough for a long time now, at least 6 months. I cough mostly when I lay down at night. It used to be a dry cough, bit lately it s looser. I have been coughing more.. I don t feel sick, am just really tired all the time. When should I be more concerned about this?  <response>: Hi, I understand you are worried about your chronic cough cough more than 8 weeks. Chronic cough associated with fatigue warrants complete history taking and work up. Since Im not sure about your age, geographical area, occupational history, and social history, I would like to give you an overview. It could be caused by a discharge from the back of your throat what we call post-nasal Chat Doctor. 