Health risks are reduced substantially even if you quit at age 70. The National Cancer Institute says that, on average, after 10 to 15 years, a previous tobacco user's risk of premature death approaches that of a person who has never smoked. People who stop smoking before age 35 avoid 90 percent of the health risks attributable to tobacco. Even those who quit later in life can significantly reduce their risk of dying at a younger age. Smokers who quit before age 50, on average, have half the risk of dying in the next 16 years compared with people who continue to smoke. By age 64, their overall chance of dying is similar to that of people the same age who have never smoked. People who quit smoking cut their risk of lung cancer by 30 to 50 percent after 10 years compared with continuing smokers, and cut their risk of oral and esophageal cancer in half within five years of quitting.

According to the U.S. Surgeon General's Report of 1990, the excess risk of coronary heart disease is half that of a smoker's, and after 15 years smoke-free, the risk levels drop to that of someone who never smoked.

The success rate is 30 percent among those who enter smoking-cessation programs with counseling and support.

The success rate doubles among those in a program that includes follow-up appointments and a set quit date. A study reported in February 2005 by the National Heart, Lung, and Blood Institute found that an intervention program of behavior modification (counseling), nicotine gum, and a continuing five-year maintenance to minimize relapse helped about 22 percent of the participants become sustained quitters five years after the program; nearly 90 percent of them continued not to smoke after 11 years. About 5 percent of those who did not receive the intervention were sustained quitters after five years.

Almost 50 percent of the attempts to quit are supported with the patch. Gum is used 28 percent of the time; medication, 21 percent.

Women smokers are 54 percent less likely to conceive than nonsmokers within a year of attempting to get pregnant. Smoking also reduces men's sperm count.

Smoking at an early age results in a more severe addiction as an adult.

About 25 percent of 12- and 13-year-olds have smoked.

Today, more than 45 million Americans smoke.