Snapshot A 29-year-old man presents to the emergency department with severe pleuritic chest pain. He tells the resident that he is worried he might have another collapsed lung. His temperature is 98.7°F (37.1°C), blood pressure is 118/78 mmHg, pulse is 119/min, respirations are 31/min, and oxygen saturation is 85% on room air. On examination, he appears cachectic. A chest radiograph is obtained. Introduction Clinical definition login to view 11 more bullets Epidemiology Demographics login to view 2 more bullets Risk factors login to view 4 more bullets ETIOLOGY Pathogenesis login to view 3 more bullets Presentation Symptoms login to view 4 more bullets Physical exam login to view 10 more bullets imaging Chest radiograph login to view 4 more bullets Computed tomography login to view 1 more bullet studies Pulmonary function tests (PFTs) login to view 17 more bullets Arterial blood gas (ABG) login to view 6 more bullets Differential Asthma login to view 2 more bullets Bronchiectasis login to view 4 more bullets Interstitial lung disease (ILD) login to view 2 more bullets Treatment First-line login to view 31 more bullets Second-line login to view 2 more bullets Complications Acute exacerbation Pneumothorax login to view 1 more bullet