What is bullae in lungs?

Enlarged air sacs: Bullae occur when the normal air sacs of the lungs collapse into themselves causing larger and larger air spaces.

Emphysema: A bulla is an air space in the lung measuring more than one centimeter in diameter in the distended state. Giant bullae develop as a result of cigarette smoking. Patients with HIV and IV drug users can also have bullous lung disease. Patients may have shortness of breath with exertion or at rest. Surgical removal is called bullectomy.