Pneumonia is a common Lung infection characterised by collection of pus and other fluids in the Lung Air Sacs (alveoli). Lung air sacs are structures that help in the exchange of oxygen and carbon dioxide. Collection of pus in them makes breathing difficult. Pneumonia can be in one area of a lung or be in several areas (“double” or “multilobar” pneumonia). Many things can cause a pneumonia—though most often they are infectious.
