The chronic cough experienced by smokers because smoking impairs the lung's ability to clean out harmful material. Coughing is the body's way of trying to get rid of the harmful material in the lungs. An oily substance resulting from the burning of tobacco and consisting of thousands of chemicals, some of which are carcinogenic or otherwise harmful, Teratogen. Many of the chemicals in tobacco smoke are known teratogens. A condition in which higher doses of a drug are required to produce the same effect as during initial drug use.
Tolerance often leads to physical dependence.
Common triggers include stressful events, driving in the car, drinking alcohol, watching TV, negative emotions, and breaks from work. Some urges are strong enough that a recently quit smoker may experience a lapse or relapse. Withdrawal symptoms are thought to increase the risk for relapse. A prescription smoking cessation medication that contains bupropion in a sustained-release formulation.