Overview

Smoking harms your lungs in many ways. Quitting smoking is the most important thing you can do to slow down the disease and improve your quality of life.

Smoking is linked to:

• Lung cancer. Most lung cancer is caused by smoking. After you quit, your risk for lung cancer drops over time. The risk continues to go down as the number of years you stay smoke-free increases.
• Chronic obstructive pulmonary disease (COPD). The most common cause of COPD is smoking. Smoking further damages the breathing tubes and lung tissue when you have COPD. Quitting smoking stops the ongoing damage caused by tobacco smoke.
• More frequent or worse asthma attacks. People with asthma who quit smoking usually have fewer, shorter asthma attacks.
• More infections. People who smoke have more colds, influenza (flu), and pneumonia than people who don't smoke. After you quit smoking, you will probably have fewer of these illnesses.

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.