How do lung bullae form?

Bullae are large vacuoles that replace normal lung tissue on chest imaging, often resulting from emphysema. When people inhale cigarette smoke or other harmful gases or dust, these harmful gases and smoke particles deposit in the bronchi and alveoli, triggering a chronic inflammatory response. This chronic inflammatory reaction will destroy the bronchioles and alveoli of the lungs, causing destruction of the alveoli. After a large number of alveoli are destroyed and fused, pulmonary bullae will form. Pulmonary bullae are an imaging diagnosis, mainly seen in chronic obstructive pulmonary disease, which is more common in the elderly. The main symptoms are chronic cough and expectoration, and chest tightness and shortness of breath after activity.