<prompt> Sudden onset of cough followed by increased dyspnea is typical of-PneumothoraxLobar pneumoniaCollapse of lungAcute pleurisy  <response>: Causes of pneumothorax: 1. Primary spontaneous: arupture of apical blebs bsmokers 2.secondary : acopd and any other lung disease 3. Traumatics secondary to thoracentesis,central intravenous catheters 4.tension pneumothorax: during mechanical ventilation may cause decreased venous return and decreased cardiac output. 