Pneumothorax is defined as air in the pleural space between the lungs and chest wall. It is classified as spontaneous, traumatic, or iatrogenic. A tension pneumothorax occurs when air enters the pleural space during inspiration but cannot escape during expiration, increasing pressure on the lungs and blood vessels. Symptoms include chest pain and difficulty breathing. Diagnosis is made through chest x-ray. Treatment for primary pneumothorax is needle aspiration or tube drainage if symptoms are severe. Secondary and tension pneumothoraces require tube drainage as they can cause respiratory failure. Tube drainage involves inserting a catheter through the chest wall and connecting it to suction to remove air from the pleural space.