A pneumothorax occurs when air enters the pleural space between the visceral pleura and parietal pleura causing partial or complete lung collapse. Mediastinal shifting usually occurring with distant to absent breath sounds on the affected side.
Sudden onset of acute pleuritic chest pain on the affected side usually occurs with labored breathing and dyspnea.
Other problems that may occur include uneven chest wall movement, tachycardia, respiratory distress (severe tachyapnea).