2004 Surgeon General’s Report – Highlights (English)

• Smoking harms nearly every organ of the body, causing many diseases and reducing the health of smokers in general.
• Quitting smoking has immediate as well as long-term benefits, reducing risks for diseases caused by smoking and improving health in general.
• Smoking cigarettes with lower machine-measured yields of tar and nicotine provides no clear benefit to health.
• The list of diseases caused by smoking has been expanded to include abdominal aortic aneurysm, acute myeloid leukemia, cataract, cervical cancer, kidney cancer, pancreatic cancer, pneumonia, periodontitis, and stomach cancer. These are in addition to diseases previously known to be caused by smoking, including bladder, esophageal, laryngeal, lung, oral, and throat cancers, chronic lung diseases, coronary heart and cardiovascular diseases, as well as reproductive effects and sudden infant death syndrome.

Since the first Surgeon General’s report on smoking and health in 1964, 27 additional reports have concluded that tobacco use is the single most avoidable cause of disease, disability, and death in the United States.

These reports have assembled the scientific data on smoking and many related diseases and then evaluated the data to assess whether or not smoking could be classified as the cause of a particular disease. Using this approach, almost every report since 1964 has expanded the list of diseases caused by tobacco use.

Since the first causal conclusions in 1964, there has been increasing evidence to support those earlier conclusions. The 2004 report of the surgeon general, The Health Consequences of Smoking, updates the evidence and conclusions of the impact of smoking on health.

Using terminology already in use by the Institute of Medicine and the International Agency for Research on Cancer, this methodology clarifies what is meant by each conclusion in this Surgeon General’s report. Conclusions on whether smoking causes diseases are classified in the following way:

For the Surgeon General to conclude that smoking is proven to cause a particular disease, there must be enough scientific evidence that smoking either increases the overall number of cases of the disease or makes the disease occur earlier than it otherwise would. The reports use a number of criteria to guide their judgment:

• Do multiple high-quality studies show a consistent association between smoking and disease?
• Are the measured effects large enough and statistically strong?
• Does the evidence show that smoking occurs before the disease occurs (a temporal association)?
• Is the relationship between smoking and disease coherent or plausible in terms of known scientific principles, biologic mechanisms, and observed patterns of disease?
• Is there a dose-response relationship between smoking and disease?
• Is the risk of disease reduced after quitting smoking?

As a companion resource for scientists, medical students, and others, an interactive database of more than 1,600 articles cited in the Surgeon General’s report is available through the Internet at http://apps.nccd.cdc.gov/SGR/search.aspx. The database is easily accessible and can serve as a primary source of information about smoking-related disease research. The user can select search criteria to see results from the key studies cited in this report on topics such as cancer, cardiovascular diseases, respiratory diseases, reproductive effects, and other health effects. The user also can develop customized analyses, tables, and figures by using the interactive features of the database.

• Toxic ingredients in cigarette smoke travel throughout the body, causing damage in several different ways. (p. 616)
• Nicotine reaches the brain within 10 seconds after smoke is inhaled. It has been found in every part of the body and in breast milk. (p. 616)
• Carbon monoxide binds to hemoglobin in red blood cells, preventing affected cells from carrying a full load of oxygen. (p. 616)
• Cancer-causing agents (carcinogens) in tobacco smoke damage important genes that control the growth of cells, causing them to grow abnormally or to reproduce too rapidly. (pp. 44–45)
• The carcinogen benzo[a]pyrene binds to cells in the airways and major organs of smokers. (p. 616)
• Smoking affects the function of the immune system and may increase the risk for respiratory and other infections. (p. 616)
• There are several likely ways that cigarette smoke does its damage. One is oxidative stress that mutates DNA, promotes atherosclerosis, and leads to chronic lung injury. Oxidative stress is thought to be the general mechanism behind the aging process, contributing to the development of cancer, cardiovascular disease, and COPD. (p. 619)
• The body produces antioxidants to help repair damaged cells. Smokers have lower levels of antioxidants in their blood than do nonsmokers. (pp. 618–619)
• Smoking is associated with higher levels of chronic inflammation, another damaging process that may result from oxidative stress. (p. 619)

• Research has shown that women’s smoking during pregnancy increases the risk of pregnancy complications, premature delivery, low-birth-weight infants, stillbirth, and sudden infant death syndrome (SIDS). (pp. 527, 601)
• The nicotine in cigarettes may cause constrictions in the blood vessels of the umbilical cord and uterus, thereby decreasing the amount of oxygen available to the fetus. Nicotine also may reduce the amount of blood in the fetal cardiovascular system. (p. 564)
• Nicotine is found in breast milk. (p. 616)
• Babies of mothers who smoked during pregnancy have lower birth weights. Low birth weight is a leading cause of infant deaths. (p. 527, Martin et al. 2002)
• In general, pregnant smokers eat more than pregnant nonsmokers, yet their babies weigh less than babies of nonsmokers. This weight deficit is smaller if smokers quit early in their pregnancy. (pp. 564–565)
• Smoking by the mother causes sudden infant death syndrome (SIDS). Compared with unexposed infants, babies exposed to secondhand smoke after birth are at twice the risk for SIDS, and infants whose mothers smoked before and after birth are at three to four times greater risk. (pp. 584–585, 601)
• Mothers’ smoking during pregnancy reduces their babies’ lung function. (pp. 467, 508)
• In 2001, 17.5% of teenaged mothers smoked during pregnancy. Only 18% to 25% of all women quit smoking once they become pregnant. (pp. 527, 550)
• Children and adolescents who smoke are less physically fit and have more respiratory illnesses than their nonsmoking peers. In general, smokers’ lung function declines faster that that of nonsmokers. (pp. 485, 509)
• Smoking by children and adolescents hastens the onset of lung function decline during late adolescence and early adulthood. (pp. 473–474, 508–509)
• Smoking by children and adolescents is related to impaired lung growth, chronic coughing, and wheezing. (pp. 473–474, 485, 508–509)

• Cancer is the second leading cause of death and was among the first diseases causally linked to smoking. (p. 39)
• Lung cancer is the leading cause of cancer death, and cigarette smoking causes most cases. (p. 61)
• Compared to nonsmokers, men who smoke are about 23 times more likely to develop lung cancer and women who smoke are about 13 times more likely. Smoking causes about 90% of lung cancer deaths in men and almost 80% in women. (p. 39)
• In 2003, an estimated 171,900 new cases of lung cancer occurred and approximately 157,200 people died from lung cancer. (p. 42)
• The 2004 Surgeon General’s report adds more evidence to previous conclusions that smoking causes cancers of the oral cavity, pharynx, larynx, esophagus, lung, and bladder. (pp. 42, 62, 63, 116, 166)
• Cancer-causing agents (carcinogens) in tobacco smoke damage important genes that control the growth of cells, causing them to grow abnormally or to reproduce too rapidly. (pp. 44–45)
• Cigarette smoking is a major cause of esophageal cancer in the United States. Reductions in smoking and smokeless tobacco use could prevent many of the approximately 12,300 new cases and 12,100 deaths from esophageal cancer that occur annually. (p. 119)
• The combination of smoking and alcohol consumption causes most laryngeal cancer cases. In 2003, an estimated 3800 deaths occurred from laryngeal cancer. (p. 62)
• In 2003, an estimated 57,400 new cases of bladder cancer were diagnosed and an estimated 12,500 died from the disease. (p. 166)
• For smoking-attributable cancers, the risk generally increases with the number of cigarettes smoked and the number of years of smoking, and generally decreases after quitting completely. (pp. 39, 42)
• Smoking cigarettes that have a lower yield of tar does not substantially reduce the risk for lung cancer. (p. 61)
• Cigarette smoking increases the risk of developing mouth cancers. This risk also increases among people who smoke pipes and cigars. (p. 67)
• Reductions in the number of people who smoke cigarettes, pipes, cigars, and other tobacco products or use smokeless tobacco could prevent most of the estimated 30,200 new cases and 7,800 deaths from oral cavity and pharynx cancers annually in the United States. (p. 67)

New Cancers Confirmed by This Report

• The 2004 Surgeon General’s report newly identifies other cancers caused by smoking, including cancers of the stomach, cervix, kidney, and pancreas and acute myeloid leukemia. (pp. 137, 167, 170, 183, 254, 324–325)
• In 2003, an estimated 22,400 new cases of stomach cancer were diagnosed, and an estimated 12,100 deaths were expected to occur. (p. 178)
• Former smokers have lower rates of stomach cancer than those who continue to smoke. (p. 182)
• For women, the risk of cervical cancer increases with the duration of smoking. (p. 169)
• In 2003, an estimated 31,900 new cases of kidney cancer were diagnosed, and an estimated 11,900 people died from the disease. (p. 166)
• In 2003, an estimated 30,700 new cases of pancreatic cancer were diagnosed, attributing to 30,000 deaths. The median time from diagnosis to death from pancreatic cancer is about 3 months. (p. 136)
• In 2003, approximately 10,500 cases of acute myeloid leukemia were diagnosed in adults. (p. 252)
• Benzene is a known cause of acute myeloid leukemia, and cigarette smoke is a major source of benzene exposure. Among U.S. smokers, 90% of benzene exposures come from cigarettes. (p. 252)

• Coronary heart disease and stroke—the primary types of cardiovascular disease caused by smoking—are the first and third leading causes of death in the United States. More than 61 million Americans suffer from some form of cardiovascular disease, including high blood pressure, coronary heart disease, stroke, congestive heart failure, and other conditions. More than 2,600 Americans die every day because of cardiovascular diseases, about 1 death every 33 seconds. (p. 363)
• Toxins in the blood from smoking cigarettes contribute to the development of atherosclerosis. Atherosclerosis is a progressive hardening of the arteries caused by the deposit of fatty plaques and the scarring and thickening of the artery wall. Inflammation of the artery wall and the development of blood clots can obstruct blood flow and cause heart attacks or strokes. (pp. 364–365)
• Smoking causes coronary heart disease, the leading cause of death in the United States. Coronary heart disease results from atherosclerosis of the coronary arteries. (pp. 384, 407)
• In 2003, an estimated 1.1 million Americans had a new or recurrent coronary attack. (p. 384)
• Cigarette smoking has been associated with sudden cardiac death of all types in both men and women. (p. 387)
• Smoking-related coronary heart disease may contribute to congestive heart failure. An estimated 4.6 million Americans have congestive heart failure and 43,000 die from it every year. (p. 387)
• Smoking low-tar or low-nicotine cigarettes rather than regular cigarettes appears to have little effect on reducing the risk for coronary heart disease. (pp. 386, 407)
• Strokes are the third leading cause of death in the United States. Cigarette smoking is a major cause of strokes. (p. 393)
• The U.S. incidence of stroke is estimated at 600,000 cases per year, and the one-year fatality rate is about 30%. (p. 393)
• The risk of stroke decreases steadily after smoking cessation. Former smokers have the same stroke risk as nonsmokers after 5 to 15 years. (p. 394)
• Smoking causes abdominal aortic aneurysm. (p. 397)

• Smokers are more likely to be absent from work than nonsmokers, and their illnesses last longer. (p. 627)
• Smokers tend to incur more medical costs, to see physicians more often in the outpatient setting, and to be admitted to the hospital more often and for longer periods than nonsmokers. (pp. 652–653)
• Smokers have a lower survival rate after surgery compared to that of nonsmokers because of damage to the body’s host defenses, delayed wound healing, and reduced immune response. Smokers are at greater risk for complications following surgery, including wound infections, postoperative pneumonia, and other respiratory complications. (p. 653)
• Periodontitis is a serious gum disease that can result in the loss of teeth and bone loss. Smoking is causally related to periodontitis. This may be because smoking affects the body’s ability to fight infection and repair tissue. (pp. 733, 736)
• Peptic ulcers, which are located in the digestive tract (stomach and duodenum), usually occur in people with an infection caused by the Helicobacter pylori bacterium. Among persons with this infection, smokers are more likely to develop peptic ulcers than nonsmokers. In severe cases, peptic ulcers can lead to death. (p. 805)
• Although only a small number of studies have looked at the relationship between smoking and erectile dysfunction, their findings suggest that smoking may be associated with an increased risk for this condition. More studies are needed, however, before researchers can conclude that smoking is causally related to erectile dysfunction. (p. 776)

• Smoking harms many aspects and every phase of reproduction. Despite having greater increased knowledge of the adverse health effects of smoking during pregnancy, many pregnant women and girls continue to smoke (estimates range from 12% to 22%). It is estimated that only 18% to 25% quit smoking once they become pregnant. (p. 527)
• Women who smoke are at an increased risk for infertility. Studies have shown that smoking makes it more difficult for women to become pregnant. (p. 534)
• Research also has shown that smoking during pregnancy causes health problems for both mothers and babies, such as pregnancy complications, premature birth, low-birth-weight infants, stillbirth, and infant death. Low birth weight is a leading cause of infant deaths, resulting in more than 300,000 deaths annually in the United States. (p. 555, Ventura et al. 2000)
• Once pregnant, women who smoke are about twice as likely to experience complications such as placenta previa, a condition where the placenta grows too close to the opening of the uterus. This condition frequently leads to delivery by a Caesarean section. (p. 551)
• Pregnant women who smoke also are more likely to have placental abruption, where the placenta prematurely separates from the wall of the uterus. This can lead to preterm delivery, stillbirth, or early infant death. Estimates for risk of placental abruption among smokers range from 1.4 to 2.4 times that of nonsmokers. (p. 554)
• Pregnant smokers also are at a higher risk for premature rupture of membranes before labor begins. This makes it more likely that a smoker will carry her baby for a shorter than normal gestation period. (p. 554)
• Risk for having a baby in the smallest 5% to 10% of birth weights is as high as 2.5 times greater for pregnant smokers. (p. 574)
• For reasons that are currently unknown, smokers are less likely to have preeclampsia, a condition that results in high blood pressure and an excess of protein in the urine. (p. 554)

• In 2001, chronic obstructive pulmonary disease (COPD) was the fourth leading cause of death in the United States, resulting in more than 118,000 deaths. More than 90% of these deaths were attributed to smoking. (p. 500)
• According to the American Cancer Society’s second Cancer Prevention Study, female smokers were nearly 13 times as likely to die from COPD as women who had never smoked. Male smokers were nearly 12 times as likely to die from COPD as men who had never smoked. (p. 500)
• About 10 million people in the United States have been diagnosed with COPD, which includes chronic bronchitis and emphysema. COPD is consistently among the top 10 most common chronic health conditions. (p. 499)
• Smoking is related to chronic coughing and wheezing among adults. (p. 490, 509)
• Smoking damages airways and alveoli of the lung, eventually leading to COPD. (p. 498)
• Smokers are more likely than nonsmokers to have upper and lower respiratory tract infections, perhaps because smoking suppresses immune function. (p. 425, 447)
• In general, smokers’ lung function declines faster than that of nonsmokers. (p. 482)

• Smoking reduces bone density among postmenopausal women. (p. 716)
• Smoking is causally related to an increased risk for hip fractures in men and women. (pp. 718–719)
• Of the 850,000 fractures among those over age 65 in the United States each year, 300,000 are hip fractures. Persons with a hip fracture are 12% to 20% more likely to die than those without a hip fracture. Estimated costs related to hip fractures range from $7 billion to $10 billion each year. (p. 698)
• Smoking is related to nuclear cataracts of the lens of the eye, the most common type of cataract in the United States. Cataracts are the leading cause of blindness worldwide and a leading cause of visual loss in the United States. Smokers have two to three times the risk of developing cataracts as nonsmokers. (p. 777)
• Chronic obstructive pulmonary disease (COPD) is consistently among the top 10 most common chronic health conditions and among the top 10 conditions that limit daily activities. Prevalence of COPD is highest in men and women 65 years of age and older (16.7% among men and 12.6% among women). (p. 499)