One of the very first withdrawal symptoms you will encounter after you stop smoking are going to be nicotine cravings. Even when you are smoking your body goes in and out of nicotine withdrawal. That is why you crave a cigarette in the morning and every hour or so after having your last cigarette. Nicotine cravings are directly linked to the physical addiction associated with smoking.
As you stop smoking your body is not getting the nicotine it is accustom too and it can be very uncomfortable during this period and many people take up smoking again because they want to feel normal again.
Remember that these feelings come and go and if you can make it through a few days you won’t crave nicotine nearly as much. Stopping smoking is uncomfortable but it is very doable.