Quitting smoking, the earlier the better

On average, smokers live more than 10 years less than non-smokers. Quitting before age 40 eliminates roughly 90% of the extra death risk caused by continued smoking. The earlier you quit, the more years you gain.

It costs nothing — in fact, it saves money. A pack-a-day habit costs roughly $3–$4, which you’ll no longer spend after quitting. The hard part is getting through the withdrawal period, which usually lasts a few weeks to several months.

One U.S. study that tracked participants without assigning them to groups found that current smokers have a life expectancy more than 10 years shorter than those who never smoked. Quitting before age 40 removes about 90% of this excess mortality risk. Quitting between ages 25–34 adds roughly 10 years to life expectancy; between 35–44, about 9 years; and between 45–54, about 6 years (as reported in the original source). Similar Chinese research from the 2010s shows that urban male smokers have a 1.65 times higher death risk than non-smokers (RR 1.65), while rural male smokers have a 1.22 times higher risk. After 10 years of sustained abstinence, this smoking-related risk nearly disappears.

Secondhand smoke is deadly too: in 2004, an estimated 603,000 people worldwide died from exposure to it, accounting for roughly 1% of all global deaths that year. Even if you don’t smoke yourself, you must avoid secondhand smoke, especially to protect children. Specific quitting strategies are outlined in the following sections: Section 3 (smoking cessation medications), Section 4 (setting a quit date), Section 5 (visiting a smoking cessation clinic), and Section 6 (e-cigarettes).

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