Smoking and cardiovascular disease.

Tobacco, especially cigarette, smoking is a major cause of cardiovascular disease (CVD), responsible for about one third of all CVD deaths in most Western populations. The risk of CVD death increases with increasing exposure to cigarette smoke, as measured by the number of cigarettes smoked daily, the duration of smoking, the degree of inhalation and the age of initiation. The relative risk for CVD is substantially greater in early adult life than in old age, and is associated more strongly with cigarettes than with other types of tobacco. Exposure to environmental tobacco smoke in never-smokers is also associated with 20-30% excess risk of coronary heart disease. There is convincing evidence that stopping smoking works, even after a heart attack, and that the excess risk declines fairly rapidly, with the risk approaching the level of never-smokers within about 10 years of quitting. Although the smoking prevalence has declined dramatically over the last few decades in many Western populations, it is increasing rapidly in most developing countries, with an emerging epidemic of tobacco related death.