I suddenly developed a dry, persistent cough about six months ago. I was a light smoker for several years, but quit smoking after developing this cough. It has now been two months since I ve quit but I still have the cough. No mucus at all. No other symptoms at all. Just a few months before developing this cough I had a complete physical with chest x-ray and the doc said things looked fine. I ve combed the internet and everything possible seems to have other symptoms. What could this cough be from? I did read that some smokers coughs can take 1-9 months to clear but most say it should go away within a few weeks after quitting smoking.