What it is

Chronic obstructive pulmonary disease, or COPD, refers to a group of diseases that cause airflow blockage and breathing-related problems. It includes emphysema, chronic bronchitis, and in some cases asthma.

COPD is a leading cause of death, illness, and disability in the United States. In 2000, 119,000 deaths, 726,000 hospitalizations, and 1.5 million hospital emergency departments visits were caused by COPD. An additional 8 million cases of hospital outpatient treatment or treatment by personal physicians were linked to COPD in 2000.

What causes it

In the United States, tobacco use is a key factor in the development and progression of COPD, but asthma, exposure to air pollutants in the home and workplace, genetic factors, and respiratory infections also play a role. In the developing world, indoor air quality is thought to play a larger role in the development and progression of COPD than it does in the United States.

Who has it

In the United States, an estimated 10 million adults had a diagnosis of COPD in 2000, but data from a national health survey suggest that as many as 24 million Americans are affected.

From 1980 to 2000, the COPD death rate for women grew much faster than the rate for men. For U.S. women, the rate rose from 20.1 deaths per 100,000 women to 56.7 deaths per 100,000 women over that 20-year span, while for men the rate grew from 73.0 deaths per 100,000 men to 82.6 deaths per 100,000 men.

U.S. women also had more COPD hospitalizations (404,000) than men (322,000) and more emergency department visits (898,000) than men (551,000) in 2000. Additionally, 2000 marked the first year in which more women (59,936) than men (59,118) died from COPD.

However, the proportion of the U.S. population aged 25-54, both male and female, with mild or moderate COPD has declined over the past quarter century, suggesting that increases in hospitalizations and deaths might not continue.

Why women's COPD rates are rising so much faster than men's

These increases probably reflect the increase in smoking by women, relative to men, since the 1940s. In the United States, a history of currently or formerly smoking is the risk factor most often linked to COPD, and the increase in the number of women smoking over the past half-century is mirrored in the increase in COPD rates among women. The decreases in rates of mild and moderate COPD in both men and women aged 25-54 in the past quarter century reflect the decrease in overall smoking rates in the United States since the 1960s.

How COPD can be prevented

Early detection of COPD might alter its course and progress. A simple test can be used to measure pulmonary function and detect COPD in current and former smokers aged 45 and over and anyone with respiratory problems. Avoiding tobacco smoke, home and workplace air pollutants, and respiratory infections are key to preventing the initial development of COPD.