A tension pneumothorax is an immediate life-threatening condition that requires prompt recognition and treatment to prevent the patient's imminent demise. The diagnosis must be suspected based upon the patient's prior medical history, the mechanism of injury, physical examination findings, and a patient in extremis. Importantly, treatment must not be delayed to obtain further diagnostic testing (e.g., chest radiograph). These patients most often present with acute and dramatic cardiopulmonary compromise, which may be manifest by a combination of the following signs and symptoms: respiratory distress, chest pain, air hunger, hypotension, tachycardia, diaphoresis, unilateral absence of or decrease in breath sounds, hyperresonance to percussion, increased central venous pressure, hypoxemia, cyanosis, deviation of the cardiac point of maximal impulse, and tracheal deviation.