What is the difference between a pneumothorax and a hemothorax?

A pneumothorax is a collection of air in the pleural space that collapses the lung, caused by trauma, surgery, or spontaneous rupture of a bleb. Signs include sudden sharp chest pain, dyspnea, absent breath sounds on the affected side, tracheal deviation toward the unaffected side in tension pneumothorax, and hyperresonance to percussion. A hemothorax is a collection of blood in the pleural space, usually from chest trauma or surgery. Signs include dyspnea, decreased breath sounds, dullness to percussion, and signs of hypovolemia like tachycardia and hypotension.