Pulmonary emphysema is a type of chronic obstructive pulmonary disease (COPD) characterized by the loss of individual alveolar wall structures, resulting in larger and less efficient alveoli with air trapping. Shortness of breath begins gradually; it may take years for affected patients to seek treatment. Other findings include wheezing, cough, chest pain, cyanosis, and increased heart rate.

Emphysema is a chronic medical condition. While pharmacologic and lifestyle changes may improve symptoms, in general, patients have a gradual increase in symptoms and burden of disease with time. The primary cause is smoking and/or inhalation of other pollutants. Pulmonary emphysema can also be secondary to alpha-1 antitrypsin deficiency, which leads to unopposed elastase activity in the lung. Treatments include lifestyle changes, supplemental oxygen, medications, and possibly surgery.