How easy is it to recover from a collapsed lung?

Negative pressure: A collapsed/punctured lung is serious, as it progresses quickly to a tension pneumothorax. Once recognized, a chest tube is placed to release the pressure associated with collapsed lung. The tube is put to negative pressure, so lung can re-expand. Recovery depends on the size and rate of healing of the injury to your lung. So a small injury should heal in days, larger injury will take longer.

Patience: The hole in the lung from trauma or spontaneous collapse can potentially seal in just a few days (like a scab). The lung tissue takes longer to fully heal, depending on type and extent of initial injury. If from trauma, associated chest wall injury (rib fractures, etc...) as well as chest tube site may take weeks to months to heal.