University of Iowa Health Science Relations
First Published: 2000
Last Revised: February 2004
Peer Review Status: Internally Peer Reviewed

For people suffering from Chronic Obstructive Pulmonary Disease (COPD), breathing in and out is anything but easy. Normal breathing is a two-step process starting with contractions of the diaphragm creating a vacuum in the lungs. This results in air moving passively into the lungs (inhale). When enough air has been inhaled, the diaphragm stops contracting and the lungs passively allow air to move out (exhale).

This process is impaired or altered in people with COPD. The diaphragm does not work as well, lungs become hyperinflated from air trapped in the lungs, and exhalation becomes an active process, resulting in increased work of breathing.

COPD is an umbrella term used to describe the co-existence of emphysema and chronic bronchitis.

Emphysema destroys the air sacs and/or the smallest breathing tubes in the lungs. Lungs lose their elasticity, much like an overused rubber band, and air sacs become enlarged, trapping air in the sacs and impairing the exchange of oxygen and carbon dioxide. Symptoms include a cough, shortness of breath, and limited exercise tolerance.

Emphysema is a progressive disease that develops after years of exposure to smoking or pollution. Cigarette smoking is the primary cause.

Several treatments are available to help minimize the symptoms of emphysema and potentially decrease the rate of progression, but one of the most important treatments is one you can do--stop smoking. Stopping at any point in the development of the disease will provide some benefit.

Chronic bronchitis is an inflammation and eventual scarring of the lining of the bronchial tubes. Long-time irritation of the bronchial tubes causes the formation of excessive mucus and the lining of the bronchial tubes becomes thickened, an irritating cough develops, air flow may be hampered, and the lungs are endangered. The bronchial tubes then make an ideal breeding place for infections.

Initially patients with early chronic bronchitis look normal in appearance, but as time passes the lips and skin may appear blue (from decreased oxygenation of tissues), feet swell, and there may be abnormal sounds in the lungs.

The treatment of chronic bronchitis is aimed at reducing irritation in the bronchial tubes. The discovery of antibiotic drugs has been helpful in treating acute infection associated with chronic bronchitis. Cigarette smoking is by far the most common cause of chronic bronchitis.

A look at Chronic Obstructive Pulmonary Disease (COPD)*

• COPD is the fourth leading cause of death in the U.S. for people between the ages of 65 to 84.
• More than 122,000 Americans died of COPD in 2000.
• The annual cost to the nation is approximately $32.1 billion.
• An estimated 11 million Americans were diagnosed with chronic bronchitis in 2001.
• An estimated 2.2 million Americans have been diagnosed with emphysema.
• Women have higher rates of chronic bronchitis while men have higher rates of emphysema.
• Approximately 80 to 90 percent of COPD cases are caused by smoking.
• A smoker is 10 times more likely than a nonsmoker to die of COPD.

* Figures from the American Lung Association.