The epidemiology of smoking: health consequences and benefits of cessation.

Tobacco use is the single most important preventable health risk in the developed world, and an important cause of premature death worldwide. Smoking causes a wide range of diseases, including many types of cancer, chronic obstructive pulmonary disease, coronary heart disease, stroke, peripheral vascular disease, and peptic ulcer disease. In addition, smoking during pregnancy adversely affects fetal and neonatal growth and development. Recent decades have seen a massive expansion in tobacco use in the developing world and accelerating growth in smoking among women in the developed world. Globally, smoking-related mortality is set to rise from 3 million annually (1995 estimate) to 10 million annually by 2030, with 70% of these deaths occurring in developing countries. Many of the adverse health effects of smoking are reversible, and smoking cessation treatments represent some of the most cost effective of all healthcare interventions. Although the greatest benefit accrues from ceasing smoking when young, even quitting in middle age avoids much of the excess healthcare risk associated with smoking. In order to improve smoking cessation rates, effective behavioural and pharmacological treatments, coupled with professional counselling and advice, are required. Since smoking duration is the principal risk factor for smoking-related morbidity, the treatment goal should be early cessation and prevention of relapse.