Smoking cessation will reduce smokers' risk of tobacco-related morbidity and mortality in the short and long term.

The immediate health benefits of quitting include a 50% reduced risk of coronary heart disease and a decrease in respiratory symptoms and infections. Long-term health benefits are substantial. Risks of lung cancer, other cancers, heart attack, stroke and chronic lung disease are significantly reduced. Smokers who quit before age 50 cut their risk of death by 50% 15 years after quitting and gain an average of about 6 years of life expectancy. Those who quit before middle age gain about ten years and have survival patterns similar to never smokers.

1. US Department of Health and Human Services. The health benefits of smoking cessation. 1990. http://profiles.nlm.nih.gov/NN/B/B/C/T/
2. Doll R, Peto R, Boreham J, Sutherland I. Mortality in relation to smoking: 50 years' observations on male British doctors. BMJ 2004; 328. http://bmj.bmjjournals.com/cgi/content/full/328/7455/1519