Consider your family.

Health concerns usually top the list of reasons people give for quitting smoking. This is a very real concern: smoking harms nearly every organ of the body. Half of all smokers who keep smoking will end up dying from a smoking-related illness. In the United States alone, smoking is responsible for nearly 1 in 5 deaths, and about 8.6 million people suffer from smoking-related lung and heart diseases.

Nearly everyone knows that smoking can cause lung cancer, but few people realize it is also linked to higher risk for many other kinds of cancer too, including cancer of the mouth, nose, sinuses, voice box (larynx), throat (pharynx), esophagus, bladder, kidney, pancreas, cervix, stomach, and acute myeloid leukemia.

emphysema and chronic bronchitis. These diseases make it harder to breathe, and are grouped together under the name chronic obstructive pulmonary disease (COPD). COPD causes chronic illness and disability, and gets worse 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. Pneumonia is also included in the list of diseases known to be caused by smoking.

Heart attacks, strokes, and blood vessel diseases

Smokers are twice as likely to die from heart attacks as are non-smokers. 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. Smoking can cause abdominal aortic aneurysm, in which the walls of the body's main artery weaken and separate, often causing sudden death. And men who smoke are more likely to develop erectile dysfunction (impotence) because of blood vessel disease.

Smoking causes an increased risk of macular degeneration, one of the most common causes of blindness in older people. It promotes cataracts, which cloud the lens of the eye. It also causes premature wrinkling of the skin, bad breath, gum disease and tooth loss, bad-smelling clothes and hair, and 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. Each year, smoking causes early deaths for about 443,000 people in the United States. 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.

50 cut their risk of dying in the next 15 years in half compared with those who keep smoking. Ex-smokers enjoy a higher quality of life. They have fewer illnesses like colds and the flu, lower rates of bronchitis and pneumonia, and feel more healthy than people who still smoke.

For decades the Surgeon General has reported the health risks linked to smoking. In 1990, the Surgeon General concluded.