Smoking tobacco is harmful to almost every organ in the body.
Smoking increases the risk of heart attack, lung cancer, chronic obstructive pulmonary disease, and other disorders.
Nicotine is the addictive substance present in tobacco.
People who stop using nicotine may become irritable, anxious, sad, and restless.
Nicotine is the substance in tobacco (present in cigarettes, cigars, and pipe and chewing tobacco) that users become dependent on. It is also the active ingredient in some drug products used to help people quit smoking.
Most nicotine exposure is from smoking tobacco, although children may accidentally eat it (usually cigarettes or butts left in ashtrays or sometimes nicotine gum or patches), and some people use smokeless tobacco. Nearly all smokers smoke cigarettes, only a few percent smoke cigars or pipes.
In the United States, about 45 million adults (20% of all adults) smoke. About one half of current smokers will die prematurely of a disorder caused by smoking. Smoking is so deadly because smokers inhale hundreds of other substances, including ones that can cause cancer. However, all tobacco products contain toxins and possible carcinogens. Even smokeless tobacco products are not safe alternatives to smoking. Smoking is also the most common cause of unintentional home fires in the United States. Smoking-related fires kill more than 350 people and injure more than 900 each year.