Asthma and COPD: definitions, epidemiology, and treatment guidelines.

Asthma and chronic obstructive pulmonary disease (COPD) are disorders that affect millions of people in the United States and other countries in the world. Asthma is a chronic inflammatory disease of the airways that has cellular and molecular pathways. Affected patients have recurrent episodes of wheezing, dyspnea, chest tightness, and cough that can be treated to minimize impact. COPD is a disease that is characterized by airflow limitation that is not fully reversible. Prevalence of asthma may be leveling off. Prevalence of COPD is increasing, especially in women. Although several therapies are available, many patients do not seek treatment until COPD is moderately advanced.