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Chronic Obstructive Pulmonary Disease (COPD)

COPD Overview

Chronic obstructive pulmonary disease, or COPD, is a long-lasting obstruction of the airways that occurs with chronic bronchitis, emphysema, or both. This obstruction of airflow is progressive in that it happens over time.

Chronic bronchitis is defined as a chronic (ongoing, long-term) cough not caused by another condition that produces sputum (mucus) for 3 or more months during each of the 2 consecutive years.

In chronic bronchitis, the mucous glands in the lungs become larger. The airways become inflamed, and the bronchial walls thicken. These changes and the loss of supporting alveolar (air space) attachments limit airflow by allowing the airway walls to deform and narrow the airway lumen (the inside of the airway tube).

Emphysema is an abnormal, permanent enlargement of the air spaces (alveoli) located at the end of the breathing passages of the lungs (terminal bronchioles). Emphysema also destroys the walls of these air spaces.

There are 3 types of emphysema: centriacinar emphysema, panacinar emphysema, and distal acinar emphysema or paraseptal emphysema.

In the United States, approximately 14.2 million people have been diagnosed with COPD, 12.5 million people have chronic bronchitis, and 1.7 million people have emphysema. It is estimated that there may be an additional equal number of US citizens that have COPD but who have not been diagnosed with the disorder. The number of people with COPD has increased by 41.5% since 1982.

An estimated 8-17% American men and 10-19% American women suffer from chronic airway obstruction. This obstruction decreases the rate of airflow through the lungs when a person exhales (breathes out). During the last decade, COPD has increased in women by 30%.

According to a 1985 study, death rates from COPD for patients aged 55-84 years were 200 per 100,000 men and 80 per 100,000 women in the United States. Although men had a higher death rate than women, the mortality rate due to COPD in women is expected to increase.

Worldwide data are sparse. However, because more than 1.2 billion people are exposed to smoking, the number of persons with COPD is probably quite high.

In 1990, the worldwide prevalence of COPD was estimated to be 9.4 per 1,000 in men and 7.3 per 1,000 in women.
One study in Spain determined that 9.1% of individuals aged 40-69 years had COPD. Of those individuals, 78% were men.
Overall death rates from COPD vary worldwide. For example, more than 400 deaths per 100,000 men aged 65-74 years occurred in Romania, whereas fewer than 100 deaths per 100,000 people in Japan occurred.