I had a crash which resulted in a broken clavicle, scapula, 5 broken ribs and a punctured lung. Each day the hospital staff came in to take X-rays to see if the lung was healing and fluid going down. The trauma doc indicated that the spirometer would help to exercise the lungs and encourage healing. She wanted to put in a chest tube to drain the lung, but that would have extended the stay in the hospital. It was already 5 days and I wanted desperately to go home. She allowed me to go as long as I promised to faithfully use the spirometer throughout the day, which I did. Continued to use it the next few weeks as the lung healed which I think helped. It hurt to take deep breaths, but the spirometer gave you some incentive to keep pushing past the pain and watch your progress over time.