The smoking dreams are common if not universal among ex-smokers. It is especially common when a person is off a short time period, and if it occurs within days or weeks of a quit, it is likely to be extremely disturbing and very realistic. Realistic enough in fact that the ex-smoker will wake up smelling and tasting a cigarette, convinced that he or she has actually smoked. I have had numerous clients search the house for the butt, it was that realistic of a sensation. Let me explain first why the physical sensation is so pronounced.
When first quitting, one of the early physical repairs that start up is cilia production. Cilia are tiny hair-like projections that line your trachea and bronchus, constantly sweeping particulate matter out of your lungs. When you smoked, you first slowed down, then paralyzed and would eventually destroy cilia. This is why smokers often have more colds and flues, they wipe out the first line of defense against the incoming microbes causing these illnesses.
When a person stops smoking, usually within 72 hours or so, cilia starts to regenerate. The ex-smoker may start cleaning out the lung in a matter of days. One of the early symptoms first encountered is coughing and spitting out, this is mucous and trapped matter that was never being cleaned out efficiently while smoking but now has an escape route and mechanism to start sweeping it. Ugly but good, you are starting to clean out a lot of garbage in your lung. Much of the garbage is tobacco tar--tobacco tars that have a very distinct taste and smell.
Let's say you are dreaming now, maybe a totally innocuous dream having nothing to do with smoking. While sleeping, cilia are sweeping, tobacco tars get brought up, reach sensory nerves for taste and smell and low and behold, you create a dream sequence involving a cigarette. But not only are you now dreaming, physical sensations of taste and smell persist upon awakening. This then becomes a real smoking sensation.
This gives a plausible explanation of why the dream occurred and why it was so vivid. But that is not the end of the significance of the dream. The dream can be interpreted in one of two ways upon awakening, and quit often, the ex-smoker takes it as a sign that they actually want to smoke. After all, they had been off smoking and just dreamt about it, that means they want to smoke, right?
I used to get calls in the middle of the night for clinic participants panicked by the dream. They would start off saying, "They can't believe it, off all this time and they still want to smoke." They knew they wanted to smoke because they dreamt about it. I would then ask them to describe the dream. They would tell about the vividness and realism, and they would almost always say it started to take on a nightmarish proportion. They would wake up in a sweat, often crying, thinking that they just smoked and blew the whole thing, that they were now back to square one. That all that time off smoking was wasted.
As soon as they would finish describing their feelings, I pointed out one very obvious fact. They just dreamt they smoked and assumed that meant that they wanted to smoke. They woke up and upon further clarification, they describe the dream was a nightmare. This is not the dream of someone who wants to smoke; it is the dream of someone who is afraid of smoking. This is a legitimate fear considering the ex-smoker is fighting a powerful and deadly addiction. Hence, it is a legitimate dream too. It kinds of gives you a sense of how bad you would feel if you actually do go back to smoking. Not physically speaking but psychologically. If the dream is a nightmare it makes you realize how bad this feeling is without having to actually have smoked and fallen into the grasp of nicotine addiction again. It can give you some perspective about how important not smoking is to your mental health.
The dangerous dream is when you smoke a whole pack in it, hack and cough, get socially ostracized, develop some horrible illness, end up on your death bed about to let out your final live breath-and all of a sudden wake up with a smile on your face and say, "that was great, wish I could do that when I am awake." As long as that is not the dream you were having, I wouldn't let myself get to discouraged by it. If that is the dream, then we may need to talk more.
In regards to smoking, no matter what you do in your dreams, you will be OK as long as you remember in your waking state to Never Take Another Puff!