Topic Overview

Most lung cancer is caused by smoking. After you quit, your risk for lung cancer drops gradually. By 10 years, your risk will be about half of what it would have been if you had continued to smoke. This risk continues to decline as the number of years of not smoking increases.^{footnote 1}

Two other lung diseases related to smoking are chronic bronchitis and emphysema. Either disease or the combination of both diseases is often called chronic obstructive pulmonary disease (COPD). Smoking damages the breathing tubes and lung tissue. This damage does not repair itself. But quitting smoking stops the ongoing damage caused by tobacco smoke.

People who have asthma have more frequent or worse asthma attacks if they smoke. Those who quit smoking usually have fewer, shorter asthma attacks.

People who smoke have more colds, flu, and pneumonia than people who do not smoke. After you quit smoking, you will have fewer of these illnesses. You will probably lose your "smoker's cough" 1 or 2 weeks after you quit smoking.

After you quit smoking, the damage to the lung tissue slows down. In the first days after quitting, you may notice that you cough up more mucus than usual. This is the result of your body trying to clear your lungs. But you will also notice after several weeks that you can breathe more easily, have more stamina, and, eventually, cough less.