It is absorbed in the lungs when it is smoked, and also absorbed when it is chewed. Kids who take smokeless tobacco are more likely than non-users to begin smoking. Cigarette smoke is composed of about 12 gases, including carbon monoxide and tar. The tar in cigarettes exposes the smoker to increased risk of lung cancer, emphysema and bronchial disorders. The carbon monoxide increases the chances of cardiovascular disease.
Nicotine produces effects on the head, lungs, stomach, and the nervous system.
Short-term effects include sweating, vomiting and throat irritation. Long-term effects include increased head rate and blood pressure. The most serious effects are lung cancer and stroke. Cancers of the esophagus, mouth, lips and larynx are also associated with cigarette smoking. Chewing tobacco is not safer than cigarettes just because there's no smoke.