Effects on the Lungs
Lung cancer is perhaps the best-known effect of smoking, but smoking also causes a number of other lung diseases, including:
- Bronchitis, in which the small airways in your lungs swell and close up
- Emphysema, in which the air sacs where oxygen enters your body swell up and are damaged
- Respiratory infections
Effects on the Heart and Circulation
Smoking increases heart disease risk and the risk of a blocked blood vessel. Depending where the blood vessel is, this can lead to a stroke (damage to your brain) or heart attack.
Smoking causes the blood vessels to narrow and harden, blood pressure to increase, and blood to become stickier, thicker, and less capable of carrying oxygen. All of these factors together are bad news for the heart and the whole body. People under 40 increase their heart attack risk by 5 times if they smoke.
Effects on the Skin and Eyes
Smoke is irritating not only to the lungs but also to the eyes and skin. Age-related degeneration in sight can be caused by smoking, and the risk of cataracts (cloudy eyes) is increased.
Skin cancer, reduced blood flow to the skin, more rapid skin aging, wrinkling, dryness and poor wound healing are all potential health effects of smoking.
Effects on the Mouth and Throat
Cancers of the mouth and throat, gum disease, reduction of ability to smell and taste, bad breath, mouth infections, tooth decay, coughing, and poor healing from dental work are just some of the effects of drawing cigarette smoke into the lungs through the mouth and throat.
Effects on Sexual Health
Both men's and women's fertility is reduced by smoking. It can also reduce male hormone (testosterone) levels and lead to impotence through poor blood flow. For women, smoking can interfere with the menstrual cycle, increase risk of stroke or heart attack in combination with oral contraceptives and increase risk of cervical cancer.
Effects on Digestion and Internal Organs
Irritation and ulcers in the digestive system, kidney disease, cancer of the kidneys, bladder, stomach and liver, weakness and poor healing of the bones are just some of the negative health effects of smoking on the body's internal organs and systems.
Effects on the Brain
Smokers' brains can shrink and become less effective at remembering and processing.
Overall, the harm that smoking does to the body is considerable and widespread. Every major organ and system is affected. Despite knowing this, smokers often find it difficult to stop, because the harm done by smoking is long-term while the pleasure is immediate. Nevertheless, wanting to be healthier (and protect the health of others) is a major reason people give for stopping smoking.
Health Effects of Cigarette Smoking on the Body by Mike Reeves-McMillan