Mayo Clinic Health Manager
Get free personalized health guidance for you and your family.
Get Started
About our e-newsletters
- Free e-newsletters
- Mayo Clinic expertise
- We do not share your e-mail address
Housecall, our weekly general-interest e-newsletter, keeps you up to date on a wide variety of health topics with timely, reliable, practical information, recipes, blogs, questions and answers with Mayo Clinic experts and more. Our biweekly topic-specific e-newsletters also include blogs, questions and answers with Mayo Clinic experts, and other useful information that will help you manage your health.
Housecall Archives
Mayo Clinic Housecall
Stay up to date on the latest health information.
What you get
- Free weekly e-newsletter
- Mayo Clinic expertise
- Recipes, tools and other helpful information
- We do not share your e-mail address
Causes
By Mayo Clinic staff
How your lungs work
Air travels down your windpipe (trachea) and into your lungs through two large tubes (bronchi). Inside your lungs, these tubes divide many times — like the branches of a tree — into many smaller tubes (bronchioles) that end in clusters of tiny air sacs (alveoli). The air sacs have very thin walls full of tiny blood vessels (capillaries). The oxygen in the air you inhale passes into these blood vessels and enters your bloodstream. At the same time, carbon dioxide — a waste product of metabolism — is removed and exhaled.
To force air out of your body, your lungs rely on the natural elasticity of the bronchial tubes and air sacs. When these are damaged, they lose their elasticity and partially collapse when you exhale, trapping air beyond the collapsed areas.
Causes of airway obstruction
COPD primarily refers to obstruction in the lungs from two chronic lung conditions. Many people with COPD have both.
- Emphysema. This lung disease causes inflammation within the fragile walls of the alveoli. This can destroy some of the walls and elastic fibers, which allows small airways to collapse when you exhale, impairing airflow out of your lungs.
- Chronic bronchitis. This condition, which is characterized by an ongoing cough, causes inflammation and narrowing of the bronchial tubes. Chronic bronchitis also causes increased mucus production, which can further block the narrowed tubes.
Asthmatic bronchitis — also known as bronchial asthma — refers to chronic bronchitis accompanied by contractions of the muscle fibers in the lining of the airways (bronchospasm). Chronic asthmatic bronchitis is sometimes classified as COPD.
Cigarette smoke and other irritants
In the vast majority of cases, the lung damage that leads to COPD is caused by long-term cigarette smoking. But other irritants can cause COPD, including cigar smoke, secondhand smoke, pipe smoke, air pollution and certain occupational fumes. Gastroesophageal reflux disease (GERD), which occurs when stomach acids wash back up into your esophagus, can aggravate COPD and may even cause it in some people.
In rare cases, COPD results from a genetic disorder that causes low levels of a protein called alpha-1-antitrypsin.
- Standards for the diagnosis and management of patients with COPD. American Thoracic Society. http://www.thoracic.org/sections/copd/resources/copddoc.pdf. Accessed Jan. 15, 2009.
- Gigliotti F, et al. Breathing retraining and exercise conditioning in patients with chronic obstructive pulmonary disease (COPD): A physiological approach. Respiratory Medicine. 2003;97:197.
- What is chronic obstructive pulmonary disease? National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/public/lung/copd/what-is-copd/index.htm. Accessed Jan. 15, 2009.
- Pocket guide to COPD diagnosis, management and prevention. Global Initiative for Chronic Obstructive Lung Disease. http://www.goldcopd.com/Guidelineitem.asp?l1=2&l2=1&intId=1116. Accessed Jan. 15, 2009.
- Sutherland ER, et al. Management of chronic obstructive pulmonary disease. New England Journal of Medicine. 2004;350:2589.
- COPD Fact Sheet. American Lung Association. COPD Fact Sheet.http://www.lungusa.org/site/c.dvLUK9O0E/b.252866/k.A435/COPD_Fact_Sheet.htm. Accessed Jan. 15, 2009.
- Tiep BL, et al. Long-term supplemental oxygen therapy. http://www.uptodate.com/home/index.html. Accessed Jan. 15, 2009.
