Cigarette smoking alone is directly responsible for at least one third of all cancer deaths annually in the United States, and contributes to the development of low birth weight babies and cardiovascular disease. Quitting smoking can significantly reduce a person's risk of developing heart disease and diseases of the lung, and can limit adverse health effects on unborn children. Cigarette smoking is the most significant cause of lung cancer and the leading cause of lung cancer death in both men and women.
Smoking is also responsible for most cancers of the larynx, oral cavity, and esophagus.
In addition, it is highly associated with the development of and deaths from bladder, kidney, pancreatic, and cervical cancers. The EPA report estimates that ETS is responsible for lung cancers in several thousand nonsmokers each year, and ETS exposure is also linked to severe respiratory problems in infants and young children. During smoking, nicotine is absorbed quickly into the bloodstream and travels to the brain, causing an addictive effect. The risk of developing lung and other smoking-associated cancers, as well as noncancerous diseases, is related to total lifetime exposure to cigarette smoke. This includes the number of cigarettes a person smokes each day, the age at which smoking began, the number of years a person has smoked, and ETS exposure.