<prompt> Sudden onset of cough followed by increasing dyspnea is characteristic ofPleural effusionLobar pneumoniaMyocardial infarctPneumothorax  <response>: PatientsMC presents with chest pain, often sharp and pleuritic and may lead to severe respiratory embarrassment or becomes dull and persistent.Dyspnea is the 2nd MC symptom.Less common symptoms include a nonproductive cough and ohopnea.Physical findings may be normal if the Pneumothorax is less than 25.Characteristic physical finding includes diminished chest excursion and Refer: Harrisons Principles of Internal Medicine, 18th edition, pg no: 2181, 2221, 3212 