Many smokers inhale more often or more deeply to compensate for low nicotine levels in these cigarettes. Many smokers report having problems sleeping after they stop smoking. If these symptoms are related to nicotine dependence, they should disappear within 2-3 weeks. About 20 percent of former smokers report an increase in coughing after they stop smoking. This is a temporary response thought to be caused by an increase in the lung's ability to remove phlegm, so it actually represents recovery of the lung's defense mechanisms.
Nicotine addiction seems to be retriggered quickly in most former smokers.
Do not risk getting hooked again. Some of the damage may be permanent, such as loss of lung tissue in emphysema. Other functions are recovered, such as the lung's ability to remove phlegm. The increased risk of heart disease due to smoking disappears in less than 10 years after stopping. The increased risk of lung cancer disappears within 15 years.