Smoking cessation has major and immediate health benefits for men and women of all ages. Quitting smoking decreases the risk of lung and other cancers, heart attack, stroke, and chronic lung disease. The earlier a person quits, the greater the health benefit. For example, research has shown that people who quit before age 50 reduce their risk of dying in the next 15 years by half compared with those who continue to smoke (3). Smoking low-yield cigarettes, as compared to cigarettes with higher tar and nicotine, provides no clear benefit to health (2). For additional information on quitting smoking, see the NCI fact sheet Questions and Answers About Smoking Cessation, which can be found at on the Internet.
Smoking harms nearly every major organ of the body (2). The risk of developing smoking-related diseases, such as lung and other cancers, heart disease, stroke, and respiratory illnesses, increases with total lifetime exposure to cigarette smoke (7). This includes the number of cigarettes a person smokes each day, the intensity of smoking (i.e., the size and frequency of puffs), the age at which smoking began, the number of years a person has smoked, and a smoker's secondhand smoke exposure.
This may explain why African Americans, who statistically smoke fewer cigarettes a day (but more menthol cigarettes), are more likely than whites to die from smoking-related diseases like lung cancer, heart disease, and stroke.
The risk for lung cancer is higher among smokers who smoke cigarettes and cigars or pipes, and for smokers who switch to cigars or pipes after years of cigarette smoking.
Tobacco smoking is the largest preventable cause of cancer, responsible for more cancer deaths in Australia than any other single factor. It is also directly responsible for many heart and lung diseases. Smoking affects the smoker, as well as those around them.
Cigarette smoking causes 87 percent of lung cancer deaths (1). Lung cancer is the leading cause of cancer death in both men and women (3). Smoking is also responsible for most cancers of the larynx, oral cavity and pharynx, esophagus, and bladder. In addition, it is a cause of kidney, pancreatic, cervical, and stomach cancers (2, 4), as well as acute myeloid leukemia (2).
Tobacco use, particularly cigarette smoking, is the single most preventable cause of death in the United States. Cigarette smoking alone is directly responsible for approximately 30 percent of all cancer deaths annually in the United States (1). Cigarette smoking also causes chronic lung disease (emphysema and chronic bronchitis), cardiovascular disease, stroke, and cataracts. Smoking during pregnancy can cause stillbirth, low birth weight, Sudden Infant Death Syndrome (SIDS), and other serious pregnancy complications (2). Quitting smoking greatly reduces a person's risk of developing the diseases mentioned, and can limit adverse health effects on the developing child.
The health risks caused by cigarette smoking are not limited to smokers. Exposure to secondhand smoke, or environmental tobacco smoke (ETS), significantly increases the risk of lung cancer and heart disease in nonsmokers, as well as several respiratory illnesses in young children (5). (Secondhand smoke is a combination of the smoke that is released from the end of a burning cigarette and the smoke exhaled from the lungs of smokers.) The U.S. Environmental Protection Agency (EPA), the National Institute of Environmental Health Science's National Toxicology Program, and the World Health Organization's International Agency for Research on Cancer (IARC) have all classified secondhand smoke as a known human carcinogen--a category reserved for agents for which there is sufficient scientific evidence that they cause cancer (5, 6, 7). The U.S. EPA has estimated that exposure to secondhand smoke causes about 3,000 lung cancer deaths among nonsmokers and is responsible for up to 300,000 cases of lower respiratory tract infections in children up to 18 months of age in the United States each year (5). For additional information on ETS, see the NCI fact sheet Environmental Tobacco Smoke, which can be found at on the Internet.
Cancer of the mouth, larynx, pharynx, esophagus, kidney, bladder, pancreas, and uterine cervix also have in common cigarette smoking as a major cause.
Eventually, the lung surface area can become so small that a person with emphysema has to spend most of the time gasping for breath, with an oxygen bottle near by or with oxygen tubes inserted into the nasal cavity.