Cigarette smokers who quit benefit almost immediately as levels of nicotine, carbon monoxide, and carcinogens in their blood drop. Blood pressure improves and ex-smokers begin to breathe easier.
The health benefits continue as the body repairs damage and recovers from the No. 1 preventable cause of death in the United States.
After 10 to 15 years, former smokers' risk of an early death drops almost to the level of people who never smoked, according to American Cancer Society data.
Lifelong smokers who quit before age 50 have half the risk of dying in the next 16 years as people who still smoke. By age 64, their overall chance of dying is similar to that of people the same age who never smoked.
Older adults who quit reduce their risk of dying from heart attacks, strokes, lung cancer, pneumonia, and other diseases.
People who plot their course toward a smoke-free life often worry about another health problem that may appear in the early days after quitting. It's the time when ex-smokers often have trouble sleeping and feel anxious, irritable, and hungry.
At the same time, their senses of smell and taste are returning, and ex-smokers put food instead of cigarettes in their mouths.
That's right. Ex-smokers often do gain weight.
Scientists at the U. S. Centers for Disease Control and Prevention (CDC) studied weight gain during the first 10 years after people stop smoking. The average man gained 9.7 pounds more than men who continued to smoke. Women who quit gained about 11 pounds more than those who kept smoking.
Smokers who quit also were about twice as likely to become overweight within 10 years as men and women who never smoked.
The 1990 U.S. Surgeon General's report concluded that the health benefits of quitting far outweigh the health risks of gaining weight. Those 10 pounds, after all, may be worth 10, 20, or 30 extra years of life.
The CDC even said it might be best to let ex-smokers gain the weight, with no effort to prevent it. Once smokers have beat dangerous nicotine addiction, they can focus on healthy weight.
Smoking cessation experts agree with that approach. As former President Harry Truman remarked during the Korean conflict when Gen. Douglas McArthur wanted to invade Mainland China, "One war at a time."
Some smokers, however, recoil at the idea of weight gain - especially younger women and men who see smoking as a distant health threat and extra fat as a here-and-now disaster.
If the pounds are a barrier to quitting cigarettes, prepare in advance.
Remember, the CDC figures are averages, with some smokers gaining little, if any, weight. Other studies have found both smaller and bigger weight gains in ex-smokers.
Before you quit: Start exercising more, get used to lower-calorie foods, and find an oral substitute (chew on a drinking straw, for instance) for cigarettes. Skin patches or other nicotine replacement therapy may help delay weight gain.