Smokers are three times as likely as nonsmokers to suffer heart attacks, and many of these are the artery-spasm type. Heart attack risks are even higher for smokers who have elevated blood pressure or increased cholesterol or who use drugs such as birth control pills. The pre-heart-attack propensity to angina pectoris is also much higher in smokers, and nicotine has been known to generate "tobacco angina"—that is, chest pain with smoking. Nicotine (and other agents in smoke) also increases the incidence of problems with the heartbeat—that is, arrhythmias.

High blood pressure and atherosclerosis are associated with an increased risk of strokes. Cerebral aneurysm (ballooning of the artery wall) occurs more commonly in smokers than in nonsmokers, and ruptured aneurysms are often fatal or at least lead to lifelong impairment. Hypertension can also be more serious in smokers; a rapid rise in blood pressure requires prompt control or it may also be fatal.

Peripheral vascular disease—that is, disease of the extremity arteries—is much more common in smokers. This may manifest as intermittent claudication (pain in the legs with walking), as the poor circulation caused by atherosclerosis and vasoconstriction reduces oxygen delivery to the muscles, leading to arterial insufficiency and pain much like that of angina pectoris. Buerger’s disease is a specific arterial disease in smokers that may be caused by a hypersensitivity or allergy to tobacco. The inflammation and scarring of the arteries of the arms and legs caused by this disease in a small number of smokers are associated with pain and decreased function. Amputation may be needed if stopping smoking or drug therapy does not help. It would seem much easier and wiser to give up smoking than body parts, or life itself.

Although snuff and chewing tobacco are less toxic because they cause less air contamination, with chronic use the nicotine absorbed from them affects the circulatory system almost as seriously as smoking. There are currently over 10 million chewers addicted to nicotine, and even though they are not exposed to smoke, and thus, have reduced lung damage and lung cancers, tobacco chewers still have the negative cardiovascular effects of nicotine and a higher incidence of mouth, tongue, and throat cancers than smokers. The smoke from cigars and pipes is not usually inhaled, so less nicotine and tars are absorbed with their use, though local irritation is possible. If we want to do ourselves a favor, particularly for our heart and blood vessels, we obviously will not use tobacco at all.

For smokers, the lungs are the other key area of concern. Chronic inhalation of tobacco smoke leads to eventual destruction of the lung tissues through a process of irritation, inflammation, and scarring. Our respiratory tract includes the oral airway, the nose and sinuses, the larynx area, the large bronchial tubes, the smaller bronchioles, and the millions of tiny alveolar sacs at the depth of lung tissue where the massive surface area that contacts the blood stream allows the various inhaled substances to be absorbed. Primarily oxygen and carbon dioxide are exchanged there, but nicotine and other liquids and gases may be absorbed as well. Carbon monoxide, sulfur and nitrogen gases, hydrogen cyanide, and various metals and chemicals may also get into the body through the lungs. The respiratory tract can be used as a route for medication, mainly to affect lung function.

Smokers have a higher than average incidence of respiratory infections, including colds and flus, bronchitis, and sinusitis. By most estimates, smokers have at least twice as great an incidence as nonsmokers of these diseases, particularly acute bronchitis and bad flus. Cigarette smoke causes a decrease in the action of the cilia, and even temporary paralysis of these fine hairs on the mucous linings, which help protect the deeper tissues by pushing out microorganisms and other foreign materials. Smoke also decreases phagocyte activity by diminishing macrophage function. The thinning and drying of the mucus itself cause the bronchial tubes to become dry and irritated. This not only decreases defenses, but leads to much of the inflammation, hoarseness, and chronic cough associated with smoking.

Chronic bronchitis, one form of chronic obstructive pulmonary disease (COPD), results from long-term irritation, loss of mucus protection, and recurrent infection secondary to smoke, with a subsequent loss of function and lung capacity. This limitation in respiratory function occurs even in early smoking. When smoking is stopped, much of the function returns, unless there is lung tissue scarring, which is irreversible. Generally, smoking decreases lung capacity and endurance and often even the desire or ability to exercise. Emphysema, the other form of COPD, results from progressive alveolar scarring and loss of lung elasticity, and thus, the diminished ability to expand and contract—the basic breathing function. The irreversible damage that occurs from the chronic inhalation of tars and nicotine can cause respiratory crippling in later years, totally limiting activity and requiring regular breathing treatments. Exposure to other chemicals, usually industrial types, can also lead to lung scarring and emphysema, especially bad when combined with smoking.

Tobacco smoke is a carcinogen (many of the poisons in cigarette smoke are known carcinogens) and is the main contributor to our most deadly cancer, cancer of the lungs. This problem used to be almost exclusive to males, but now females have been smoking more, and their rates of lung cancer and death from this disease are rapidly catching up with those of the men. Equal rights to life and death! Recent studies show that the incidence of lung cancer is higher in people with low beta-carotene levels, so this is a protective nutrient. Further research will likely reveal that other nutrient deficiencies increase cancer rates, especially low levels of the other antioxidants. This has already been shown to be true for selenium.

Smokers are from five to ten times more likely to contract lung cancer than nonsmokers. These rates are even further increased with occupational exposure to agents such as asbestos, coal, textiles, and other chemicals. With regular alcohol use, smokers have greater than fifteen times the risk of lung cancer of nonsmokers.

Many other cancer rates are higher for smokers, particularly for alcohol-drinking smokers who are exposed to other carcinogenic chemicals. Smokers also have higher rates of cancer of the bladder, cervix, pancreas, esophagus, lips, mouth, and larynx. The risks are increased even further with a high-fat diet and probably with other habits that contribute to cancer, such as emotional stress, low-fiber diets, obesity, and so on. Smoking is the major cause of cancer of the mouth, tongue, and larynx, the latter being almost exclusive to smokers. Regular alcohol use along with smoking brings an increase in gastrointestinal tract cancers as well.

The incidence of cervical cancer has recently been shown to be increased in smokers, theoretically because chemicals from the smoke get into the blood and are released into the uterus and cervix. Deficiencies of nutrients such as vitamin A and folic acid may also be contributing factors in this cancer. Smoking is further implicated in bladder cancer as the bladder is a site where cigarette carcinogenic chemicals can be concentrated.

Cigarette smoking is clearly a common allergy-addiction. Symptoms of both irritation and allergy may appear when smoking is first begun and then decrease with continued smoking. Symptoms will increase with avoidance and increase further with full withdrawal before they diminish. This is classic for allergies as well as drug addictions. In addition to tobacco smoke being an allergen, many people with other allergies or with lowered immunity are very sensitive to smoke. Some people with allergies have even noticed that certain foods may stimulate the desire to smoke; the mechanism for this is unknown.

Cigarette smoking itself lowers general immunity, causing sedation of the protective phagocytic cells and cilia, as well as other effects. Cigarette smoke may be a powerful brain allergen, as nicotine goes rapidly to the brain. Many people, nearly 50 percent according to some reports, also notice decreased thinking ability with smoking (others notice improvement). And in the long run, the increase in atherosclerosis and subsequent decrease in blood circulation to the brain lead to further memory and thinking problems and early dementia. Recent research shows a four times increased risk of Alzheimer’s disease in smokers over nonsmokers.

Cigarette smoking also increases the aging process through many effects, including chronic irritation, free-radical formation, atherosclerosis, lung inflammation, and the breathing of other toxic gases, such as carbon monoxide. The poor oxygen delivery to the skin and general dehydration of the tissues caused by smoking seem to cause an increase in deep wrinkles, or "smoker’s face." This begins soon after age 30 in smokers. By age 40–50, the facial wrinkles of smokers are similar to those of nonsmokers 20 years older. I can often correctly guess that people are smokers just by knowing their age and looking at their skin, if I have not already smelled smoke on their clothes or breath. The wrinkling and aging effects may also result from nutritional depletions associated with smoking, such as deficiencies of vitamins C, B1, and B2, folic acid, zinc, and calcium. In addition to the carbon monoxide in smoke, acetaldehyde can also weaken the tissue cross-linking, causing more skin aging.

Worldwide reports suggest that smoking also affects sexuality and reproduction. In men, it has been shown to lower sperm counts and motility and thus sexual potency and reproductive ability. Smoking may also cause genetic mutation. There appears to be a slightly higher incidence of congenital malformations in the offspring of men who smoke.

In women who smoke, there are clearly more miscarriages and smaller babies. There are many increased risks for pregnant smokers as well as for their fetuses and infants. Besides resulting in babies with lower birth weight than those of nonsmoking women, which may result from a decrease in blood circulation and thus a lower oxygen and nutrient supply to the fetus throughout pregnancy, smoking increases the incidence of miscarriages, stillbirths, congenital malformations, and early infant deaths. Nicotine gets into breast milk and may decrease its production. I believe that early nicotine exposure may cause a greater likelihood of smoking addiction in later life. Smoking around newborns and infants increases their susceptibility to many diseases, particularly colds, bronchitis, and pneumonia. The increase in the number of teenage girls who smoke creates more problems in pregnancy than occur in adult smokers; in pregnant teenagers, poor development and lack of placental circulation and oxygen lead to more fetal and newborn deaths, more hospitalized newborns, and babies that are slow to learn.