For the past few months, I often think I smell smoke. Not like something is burning, but stale smoke, like there s an ashtray nearby. But there isn t. I notice this odor or smell this scent throughout the day and night. Is this symptom in and of itself something to be concerned about? No smokers around me, no ashtrays, and it doesn t matter if I m home, in the car, at work, or out in public. It s so annoying.