Smoking is the leading cause of COPD. The risk of having COPD rises with the amount of smoking and the time spent smoking. About 80 percent of people with COPD are current or former smokers. 

Smoking causes COPD by irritating the lungs’ airways and alveoli with the toxic particles and gases in cigarette smoke. The lungs’ airways become damaged and the alveoli destroyed.

Other risks for COPD include: 

• Exposure to secondhand smoke.
• Exposure to air pollution, chemicals, or industrial dust.
• Frequent use of cooking gas or fires without proper ventilation.
• Asthma.
• Genetics. Rare genetic disorders can cause COPD. Other inherited factors can make people more likely to get COPD, especially when they also smoke.

Last Updated May 2023