<unk> , also known as walking pneumonia, is any type of pneumonia not caused by one of the pathogens most commonly associated with the disease. Its clinical presentation contrasts to that of<unk> " pneumonia. A variety of microorganisms can cause it. When it develops independently from another disease, it is called primary<unk>  (PAP). The term was introduced in the 1930s and was contrasted with the bacterial pneumonia caused by Streptococcus pneumoniae, at that time the best known and most commonly occurring form of pneumonia. The distinction was historically considered important, as it differentiated those more likely to present with<unk> " respiratory symptoms and lobar pneumonia from those more likely to present with<unk> " generalized symptoms (such as fever, headache, sweating and myalgia) and bronchopneumonia.
Atypical pneumonia
Fungal pneumonia
Lobar pneumonia
Dust pneumonia
Viral pneumonia
Bacterial pneumonia
Lipid pneumonia
Lung abscess