Chronic obstructive pulmonary disease: diagnostic considerations.

Chronic obstructive pulmonary disease is characterized by the gradual progression of irreversible airflow obstruction and increased inflammation in the airways and lung parenchyma that is generally distinguishable from the inflammation caused by asthma. Most chronic obstructive pulmonary disease is associated with smoking, but occupational exposure to irritants and air pollution also are important risk factors. Patients with chronic obstructive pulmonary disease typically present with coughing, sputum production, and dyspnea on exertion. However, none of these findings alone is diagnostic. The Global Initiative for Chronic Obstructive Lung Disease diagnostic criterion for chronic obstructive pulmonary disease is a forced expiratory volume in one second/forced vital capacity ratio of less than 70 percent of the predicted value. Severity is further stratified based on forced expiratory volume in one second and symptoms. Chest radiography may rule out alternative diagnoses and comorbid conditions. Selected patients should be tested for alpha1-antitrypsin deficiency. Arterial blood gas testing is recommended for patients presenting with signs of severe disease, right-sided heart failure, or significant hypoxemia. Chronic obstructive pulmonary disease also is a systemic disorder with weight loss and dysfunction of respiratory and skeletal muscles.