What Causes COPD?
Over time, exposure to irritants that damage your lungs and airways can cause chronic obstructive pulmonary disease (COPD), which includes chronic bronchitis and emphysema. The main cause of COPD is smoking, but nonsmokers can get COPD too.
Smoking
About 85 to 90 percent of all COPD cases are caused by cigarette smoking. When a cigarette burns, it creates more than 7,000 chemicals, many of which are harmful. The toxins in cigarette smoke weaken your lungs' defense against infections, narrow air passages, cause swelling in air tubes and destroy air sacs—all contributing factors for COPD.
Your Environment
What you breathe every day at work, home and outside can play a role in developing COPD. Long-term exposure to air pollution, secondhand smoke and dust, fumes and chemicals (which are often work-related) can cause COPD.
Alpha-1 Deficiency
A small number of people have a rare form of COPD called alpha-1 deficiency-related emphysema. This form of COPD is caused by a genetic (inherited) condition that affects the body's ability to produce a protein (Alpha-1) that protects the lungs.
COPD Risk Factors
Smoking is the biggest risk factor for chronic obstructive pulmonary disease (COPD), which includes chronic bronchitis and emphysema. It increases your risk of both developing and dying from COPD. Approximately 85 to 90 percent of COPD cases are caused by smoking. Female smokers are nearly 13 times as likely to die from COPD as women who have never smoked; male smokers are nearly 12 times as likely to die from COPD as men who have never smoked.
Other risk factors for COPD include:
- Exposure to air pollution
- Breathing secondhand smoke
- Working with chemicals, dust and fumes
- A genetic condition called Alpha-1 deficiency
- A history of childhood respiratory infection
5 Steps to Reduce Your Risk for COPD
If you are concerned about getting COPD, there are steps you can take to protect yourself.
- If you are a smoker, STOP SMOKING. Quitting smoking is the single most important thing a smoker can do to live a longer and healthier life. The American Lung Association has many programs to help you quit for good.
- If you don't smoke, don't start. Smoking causes COPD, lung cancer, heart disease and other cancers.
- Avoid exposure to secondhand smoke. Make your home smokefree. You'll not only protect yourself, but your family too. Learn about your rights to a smokefree environment at work and in public places.
- Be aware of other dangers. Take care to protect yourself against chemicals, dust and fumes in your home and at work.
- Help fight for clean air. Work with others in your community to help clean up the air you and your family breathe.
Reviewed and approved by the American Lung Association Scientific and Medical Editorial Review Panel.
Page last updated: March 14, 2023