Chronic Obstructive Pulmonary Disease: Overview and Risk Factors

Chronic obstructive pulmonary disease (COPD) is a severe, irreversible disease of the lungs caused by smoking. COPD affects 14 million Americans and is the fourth most common cause of death in the United States. The rate of this disease is on the rise, due to increasing worldwide cigarette use and air pollution.

COPD comprises two entities: chronic bronchitis and emphysema.

Chronic bronchitis is characterized by inflammation, excessive mucus production, and scarring of the airways. This results in obstruction of airflow, with symptoms of difficult breathing and chronic productive cough.

In emphysema, the air sacs in the lungs become damaged, resulting in weakened lung walls and the development of large holes in the alveoli. As a consequence, the lungs become restricted during exhalation and air cannot be sufficiently exhaled.

Other common symptoms include fatigue, weakness, wheezing, shortness of breath, chest or abdominal pain, swelling in the legs, and fever.

Risk Factors

• Smoking: Cigarette smoking is the most important risk factor for COPD, and it accounts for more than 90 percent of cases. Secondhand smoke also contributes to COPD.
• Occupation:  A number of occupational pollutants, especially aerosol sprays and fine airborne particles, have been linked to an increased risk for COPD.
• Air pollution: The role of pollutants in the pathogenesis of COPD is unclear. However, the incidence of COPD is significantly increased in heavily polluted areas.
• Genetics: There is a clear genetic tendency toward the development of COPD, although specific genes have yet to be identified.