ABSTRACT

Chronic obstructive pulmonary disease (COPD) is a pulmonary disease, frequently occurring in older adults and characterized by the presence of chronic and progressive diffuse expiratory airflow limitation. The label COPD is now virtually generally accepted, bringing to a close a long-lasting debate. In contrast, a universally accepted definition of COPD is still lacking, which is one of the many causes of its late recognition, even in our western societies. Problems with definition result from what is to be understood by ‘‘chronic’’ and ‘‘progressive’’ and by ‘‘expiratory airflow limitation.’’ The definition of COPD is also affected by difficulties in appropriate labeling of its components, the airway and parenchymal components, and by the reference be made to the associated features, chronic hypersecretion, reversibility of obstruction, and airway hyperresponsiveness (1,2).