Secondhand smoke - risks; Cigarette smoking - risks; Smoking and smokeless tobacco - risks; Risks of tobacco
Tobacco is a plant. Its leaves are smoked, chewed, or sniffed for a variety of effects.
Tobacco is an addictive substance because it contains the chemical nicotine.
Tobacco contains more than 19 known cancer-causing chemicals (most are called "tar.")
HEALTH RISKS OF SMOKING OR SMOKELESS TOBACCO
There are many more reasons to quit using tobacco. Knowing the serious health risks may help motivate you to quit. When used over a long period, tobacco and related chemicals, such as tar and nicotine, can increase your risk of many health problems.
Heart and blood vessel problems:
Blood clots and aneurysms in the brain, which can lead to stroke
Blood clots in the legs, which may travel to the lungs
Parkes GT, Greenhalgh T, Griffin M, Dent R. Effect on smoking quit rate of telling patients their lung age: the Step 2 quit randomised controlled trial. BMJ. 2008:336:598-600.
Boffetta P, Straif K. Use of smokeless tobacco and risk of myocardial infarction and stroke: systematic review with meta-analysis. BMJ. 2009;339:b3060. doi: 10.1136/bmj.b3060.
U.S. Preventive Services Task Force. Counseling and interventions to prevent tobacco use and tobacco-caused disease in adults and pregnant women. U.S. Preventive Services Task Force reaffirmation recommendation statement. Ann Intern Med. 2009;150:551-555.
Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.