Your health
Health concerns usually top the list of reasons people give for quitting smoking. This is a very real concern: About half of all smokers who keep smoking will end up dying from a smoking-related illness.
Cancer
Nearly everyone knows that smoking can cause lung cancer, but few people realize it is also a risk factor for many other kinds of cancer too, including cancer of the mouth, voice box (larynx), throat (pharynx), esophagus, bladder, kidney, pancreas, cervix, stomach, and some leukemias.
Lung diseases
Pneumonia has been included in the list of diseases known to be caused by smoking since 2004. Smoking also increases your risk of getting lung diseases like emphysema and chronic bronchitis. These diseases are grouped together under the term COPD (chronic obstructive pulmonary disease). COPD causes chronic illness and disability, and worsens over time -- sometimes becoming fatal. Emphysema and chronic bronchitis can be found in people as young as 40, but are usually found later in life, when the symptoms get much worse. Long-term smokers have the highest risk of developing severe COPD.
Heart attacks, strokes, and blood vessel diseases
Smokers are twice as likely to die from heart attacks as are non-smokers. And smoking is a major risk factor for peripheral vascular disease, a narrowing of the blood vessels that carry blood to the leg and arm muscles. Smoking also affects the walls of the vessels that carry blood to the brain (carotid arteries), which can cause strokes. Men who smoke are more likely to develop erectile dysfunction (impotence) because of blood vessel disease.
Blindness and other problems
Smoking causes an increased risk of macular degeneration, one of the most common causes of blindness in older people. It also causes premature wrinkling of the skin, bad breath, bad-smelling clothes and hair, yellow fingernails.
Special risks to women and babies
Women have some unique risks linked to smoking. Women over 35 who smoke and use birth control pills have a higher risk of heart attack, stroke, and blood clots of the legs. Women who smoke are more likely to miscarry (lose the baby) or have a lower birth-weight baby. And low birth-weight babies are more likely to die, or have learning and physical problems.
Years of life lost due to smoking
Based on data collected in the late 1990s, the US Centers for Disease Control and Prevention (CDC) estimated that adult male smokers lost an average of 13.2 years of life and female smokers lost 14.5 years of life because of smoking. And given the diseases that smoking can cause, it can steal your quality of life long before you die. Smoking-related illness can limit your activities by making it harder to breathe, get around, work, or play.