<unk> . May have no signs and symptoms or they may include: * cough, but not prominent; * chest pain (not common); * breathing difficulty (fast and shallow); * low oxygen saturation; * pleural effusion (transudate type); * cyanosis (late sign); * increased heart rate. It is a common misconception and pure speculation that<unk>  causes fever. A study of 100 post-op patients followed with serial chest X-rays and temperature measurements showed that the incidence of fever decreased as the incidence of<unk>  increased. A recent review article summarizing the available published evidence on the association between<unk>  and post-op fever concluded that there is no clinical evidence supporting this speculation.
Atelectasis
Pleurisy
Emphysema
Lobar pneumonia
Pleural effusion
Pyelectasis
Hydrothorax
Atypical pneumonia