About half of all smokers die from smoking-related diseases. If you are a long-term smoker, on average, your life expectancy is about 10 years less than a non-smoker. Stopping smoking can make a big difference to your health. It is never too late to stop smoking to benefit your health. For example, if you stop smoking in middle age, before having cancer or some other serious disease, you avoid most of the increased risk of death due to smoking.