Smoking causes many premature deaths from diseases that are largely incurable, but preventable by stopping smoking. There are three main killing diseases which smoking causes or brings on earlier:
- Heart disease. Smoking is responsible for 30 percent of all heart attacks and cardiovascular deaths.
- Cancer. It is responsible for at least 30 percent of all cancer deaths and 87 percent of lung cancer deaths each year.
- Lung problems. Smoking is responsible for 82 percent of deaths due to emphysema and chronic bronchitis.
Smoking also exacerbates diseases and conditions that are not always fatal, but cause suffering or are sources of personal concern.
- Smoking delays healing of peptic ulcers of the stomach and duodenum, many of which would heal spontaneously in non-smokers.
- Its effects on blood vessels cause chronic pains in the legs (claudication) which can progress to gangrene and amputations of the toes or feet.
- An effect on elastic tissue causes wrinkling of the skin of the face to develop earlier in chronic smokers. On average they look 5 years older than non-smokers of the same age do.
- Smoking also brings on an earlier menopause in women, advancing it by an average of 5 years.
- It reduces women's fertility and delays conception after they stop using oral contraceptives.
- It impairs erections in middle-aged and older men and may affect the quality of their sperm. It seems to "sedate" sperm and to impair their motility. This is reversed after stopping smoking.
- Smoking accelerates the rate of
osteoporosis, a disease which causes bones to weaken and fracture more easily.
- Women who smoke during pregnancy damage their unborn child, causing effects that last throughout the child's life. The risks of miscarriage, premature birth, and death of the baby in its first year of life are all significantly increased.