Smoking, as well as the use of other forms of tobacco, is detrimental to health. Smokers are at higher risk for many health problems. Quitting smoking is a critical step in reducing risks of many serious health problems.
Even exposure to secondhand smoke increases the risk of lung cancer and heart disease.1, 2 In children, exposure to smoke is linked to asthma, childhood cancers, sudden infant death syndrome (SIDS), recurrent ear infections, exacerbation of cystic fibrosis, and possibly attention deficit disorder/hyperactivity.3,4,5
Warning to pregnant women: Smoking is extremely detrimental to the health of an unborn child. Exposure to smoke (including secondhand smoke) leads to decreased birth weights.6 Smoking also increases the risk of preterm deliveries, fetal mortality, childhood cancers, childhood allergies, infantile febrile seizures, urinary tract birth defects, and lower IQ.7 Smoking is also associated with decreased lactation in breastfeeding women.8
Health Problems Associated with Smoking or Exposure to Smoke
(The following list is comprehensive, although not necessarily exhaustive. Contact your health care professional for more information.)
AnginaChest pain due to reduced blood flow to the heart is known as angina or angina pectoris. Hardening of the coronary arteries that feed the heart (atherosclerosis) is usually the underlying problem. Cigarette smoking causes damage to the coronary arteries and, in this way, contributes to angina. Stopping smoking is critical for anyone with angina who smokes. Smoking has also been shown to reduce the effectiveness of treatment of angina.9 Secondhand smoke should be avoided as well.10
AsthmaAsthma is a lung disorder in which spasms of the bronchial passages restrict the flow of air in and out of the lungs. Exposure to smoke has been linked to increased risk of asthma.11 Children whose parents smoke have a higher risk of developing asthma; in addition, asthmatic children exposed to secondhand smoke have more severe asthma.12 Parents of asthmatic children who modify their smoking behavior (such as quitting or smoking outside the house) reduce the children's exposure to smoke, which should improve the health status of their child.13
AtherosclerosisAtherosclerosis, or hardening of the arteries, is a very common disease of the major blood vessels. It is characterized by fatty streaks along the vessel walls and deposits of cholesterol and calcium. Virtually all doctors acknowledge that smoking is directly linked to atherosclerosis and heart disease. Quitting smoking protects many people from atherosclerosis and heart disease and is a critical step in the process of disease prevention.
Attention Deficit Disorder, with Hyperactivity (ADD/ADHD)Smoking during pregnancy has been reported to increase the risk of giving birth to a child who develops ADD.14 For this and other negative effects on the offspring, pregnant women should not smoke.
BronchitisBronchitis is an inflammation of the trachea and bronchial tree in the lungs. Chronic bronchitis may result from prolonged exposure to bronchial irritants. Cigarette smoking, environmental toxins, and inhalant allergens can all cause chronic irritation of the bronchi. The cells lining the bronchi produce excess mucus in response to the chronic irritation; this excess mucus production can lead to a chronic, productive cough. Chronic bronchitis is frequently associated with smoking and/or environmental exposure to chemicals or allergens.15 These exposures should be avoided to allow the cells of the bronchi to recover from chronic irritation and to decrease the burden on the immune system.
CancerCancer is a general term for more than 100 diseases that are characterized by uncontrolled, abnormal growth of cells. Cancer is the second leading cause of death in Americans. Smoking has been linked to cancers of oral cavity, esophagus, lung, larynx, pancreas, cervix, bladder, kidney, prostate, and skin and possibly colonic adenomas and colon and rectal cancers.16 However, the risk of cancer decreases somewhat after quitting (particularly for cancers of the lung and pancreas). Exposure to secondhand smoke also increases the risk of lung cancer in nonsmokers,17 as well as the risk of childhood cancer in children exposed to passive smoke.18
Cardiovascular DiseaseBoth smoking19 and exposure to secondhand smoke20 increase the risk of cardiovascular disease, the number one cause of death in the United States. Smoking is linked to a lowered level of HDL cholesterol (the "good" cholesterol)21 and is also known to cause heart disease.22 Smoking has been linked to elevated triglyceride levels, another risk factor for heart disease.23 Quitting smoking significantly reduces the risk of having a heart attack.24
CataractsCataracts develop when damage to the protein of the lens of the eye clouds the lens and impairs vision. Cataracts are more likely to occur in smokers, probably because smoking causes oxidative damage. Oxidative damage to the lens of the eye appears to cause cataracts in animals25 and people.26
Chronic Obstructive Lung Disease (COLDCOLD refers to a combination of chronic bronchitis and emphysema that results in obstruction of airways. Although chronic bronchitis and emphysema are distinct conditions, smokers and former smokers often have aspects of both.
Smoking is the underlying cause of the majority of cases of emphysema and chronic bronchitis.27 Anyone who smokes should stop. Although quitting smoking will not reverse the symptoms of COLD, it can help preserve the remaining lung function. Exposure to other respiratory irritants (such as air pollution, dust, toxic gases, or fumes) can aggravate COLD and should be avoided when possible.
Common ColdSmokers have more frequent respiratory infections, such as the common cold, than nonsmokers.28
Crohn's DiseaseCrohn's disease is a poorly understood inflammatory condition that affects the final part of the small intestine and the beginning section of the colon. People with Crohn's disease are more likely to smoke, and there is evidence that continuing to smoke aggravates disease progression.29
Cystic FibrosisExposure to smoke has been found to adversely affect the growth and health of children with cystic fibrosis.30 A smoke-free environment is important to the health of children with this condition.
DiabetesPeople with diabetes cannot properly process glucose, a sugar the body uses for energy. As a result, glucose stays in the blood, causing blood glucose to rise. At the same time, however, the cells of the body can be starved for glucose.
Diabetics who smoke are at higher risk for kidney damage,31 heart disease,32 and other diabetes-related problems. Smokers are more likely to become diabetic.33 In a study of 181 diabetics, cigarette smoking was found to be a risk factor for the development of retinopathy.34
Ear Infection (Recurrent)When parents smoke, their children are more likely to have recurrent ear infections.35 To protect children from increased risk of ear infections, smoking parents should quit the habit.
Ectopic PregnancyEctopic pregnancies have been reported to be more common in women who smoke.36
EmphysemaSmoking is the underlying cause of the majority of cases of emphysema.37 Anyone who smokes should stop. Although quitting smoking will not reverse the symptoms of emphysema, it can help preserve the remaining lung function.
ExerciseSmoking leads to decreased exercise capacity.38
GastritisGastritis is a broad term for inflammation of the inner lining (mucosa) of the stomach. This condition can be caused by many factors and, in some cases, may lead to an ulcer. Heavy smoking is a known cause of acute gastritis.39
Grave's DiseaseGraves disease is a common cause of hyperthyroidism caused by an underlying autoimmune mechanism. In women, smoking has been associated with an increased risk of Grave's disease.40
HypertensionHypertension is the medical term for high blood pressure. The cause of most hypertension remains unknown. However, smoking is particularly injurious for people with hypertension.41 The combination of hypertension and smoking greatly increases the risk of heart disease-related sickness and death.
Immune FunctionSmoking impairs the function of the immune system, thereby increasing the risk of infectious disease.42
ImpotenceSmoking has an adverse effect on blood flow to the male reproductive organs and men who smoke have been shown to have an increased incidence of impotence.43
IncontinenceSmoking increases the risk of urinary incontinence in women and men.44, 45
Infertility (Female)The more women smoke, the less likely they are to conceive.46 In fact, women whose mothers smoked during their pregnancy are only half as likely to conceive as those whose mothers had been nonsmokers.47 (See Female infertility.)
InsomniaThe inability to get a good night's sleep can result from waking up in the middle of the night and having trouble getting back to sleep. It also occurs when people have a hard time getting to sleep in the first place. Insomnia can be a temporary, occasional, or chronic problem. Smokers have been reported to have an increased risk of insomnia compared with nonsmokers.48
Intermittent ClaudicationPeople with intermittent claudication experience leg pain when they walk due to a decreased blood supply resulting from atherosclerosis (hardening of the arteries). A lack of blood decreases the amount of oxygen reaching the legs, and the lack of oxygen indirectly triggers the leg pain. Smoking is directly linked to intermittent claudication.49 Quitting smoking is a critical step in the process of disease prevention.
Macular DegenerationThe macula is a portion of the retina in the back of the eye. Degeneration of the macula is the leading cause of blindness in elderly Americans.50 Smoking has been linked to macular degeneration.51 Quitting smoking may reduce the risk of developing macular degeneration.
MenopauseSmoking has been reported to increase the likelihood that a menopausal woman will experience hot flashes.52 Symptoms of menopause have also been reported to be more bothersome to smoking women compared with women who don't smoke.53 In one trial, thin women who smoked were at particularly high risk of developing hot flashes.54
Menstrual DisordersSmoking is known to affect estrogen metabolism. Perhaps as a result, women who smoke have been reported to be more likely to experience menstrual disorders such as dysmenorrhea (painful menstruation) and irregular periods.55
Mental FunctioningThough some studies suggest that smoking leads to improved cognitive performance (thinking ability), a disproportionate number of these positive studies have been funded by the tobacco industry.56 It now appears likely that "improved cognitive performance" associates with smoking only when the nonsmokers studied consist of regular smokers temporarily deprived of their cigarettes. In these people, nicotine withdrawal symptoms may be impairing mental performance, resulting in reduced ability to think compared with smokers still taking in nicotine. In one trial that avoided this problem, smoking exerted measurable negative effects on mental performance of complex information processing tasks, though simple mental tasks were not impaired by smoking.57
Musculoskeletal PainPeople who smoke are more likely to report musculoskeletal pain, including backache. Preliminary data indicate that smoking may contribute to low back pain,58 an outcome confirmed in a survey of over 29,000 people.59 A study involving 163 people with herniated discs found that both current and ex-smokers are at much higher risk of developing disc disease than nonsmokers.60 Other researchers reported 18% greater disc degeneration in the lower spines of smokers compared with nonsmokers.61 Smoking is thought to cause malnutrition of spinal discs which in turn makes them more vulnerable to mechanical stress.62
OsteoporosisPeople with osteoporosis have brittle bones, which increases the risk of bone fracture, particularly in the hip, spine, and wrist. Smoking leads to increased bone loss.63 Smoking may have this effect due to its anti-estrogenic properties.
Peptic UlcerPeptic ulcers are erosions in the stomach or duodenum (the first part of the small intestine). Ulcers can be caused or exacerbated by smoking. Smoking is known to slow ulcer healing.64
Periodontal DiseaseSmoking is a significant risk factor for the development of periodontal disease.65 Periodontal disease affects the gums, teeth, and underlying bone and is a major cause of tooth loss.
PsoriasisSmoking is linked to both the incidence of psoriasis and the exacerbation of psoriasis symptoms.66
Raynaud's DiseaseRaynaud's disease is caused by constriction and spasms of small arteries in the extremities after exposure to cold. In people with Raynaud's disease, the hands (and sometimes the toes, cheeks, nose, and ears) turn white or bluish and become painful. Individuals with Raynaud's disease should not smoke, because nicotine decreases blood flow to the extremities.67
Restless Legs SyndromeAn uncomfortable feeling of needing to move the legs is known as restless legs syndrome. One study reports that restless legs syndrome resolved in a 70-year-old woman after she stopped smoking.68 Although additional research is needed to confirm this report, a trial of smoking cessation seems prudent for people who suffer from restless leg syndrome.
Skin AgingSkin aging is a process of changes in the structure and elasticity of the skin over time. Smoking greatly exacerbates the aging of skin, leading to unattractive and prematurely old-looking skin.69 Research shows a direct relationship between smoking and the development of wrinkles.70
StrokeStrokes are caused either by a lack of blood supply to the brain or by hemorrhage within the brain. Depending on the area of the brain that is damaged, a stroke can cause coma, reversible or irreversible paralysis, speech problems, and dementia. Smoking is associated with an increased risk of stroke.71
Sudden Infant Death Syndrome (SIDS)Infants exposed to smoke have a higher risk of having SIDS. One review of 32 studies determined that mothers who smoke double the risk that their children will die from SIDS.72 Smoking by the mother during pregnancy or by either parent after the child is born increases many risks to the health of children.
1. Nyberg F, Pershagen G. Passive smoking and lung cancer. Accumulated evidence on lung cancer and environmental tobacco smoke. BMJ 1998;317:347-8.