"Primary<unk> " is called primary because it develops independently of other diseases. It is commonly known as "walking pneumonia" because its symptoms are often mild enough that one can still be up and about.<unk> " is<unk>  in that it is caused by<unk>  organisms (other than Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis). These<unk>  organisms include special bacteria, viruses, fungi, and protozoa. In addition, this form of pneumonia is<unk>  in presentation with only moderate amounts of sputum, no consolidation, only small increases in white cell counts, and no alveolar exudate. At the time that<unk>  was first described, organisms like Mycoplasma, Chlamydophila, and Legionella were not yet recognized as bacteria and instead considered viruses. Hence<unk> " was also called "non-bacterial". In literature the term<unk>  is current, sometimes contrasted with viral pneumonia (see below) and sometimes, though incorrectly, with bacterial pneumonia. Many of the organisms causative of<unk>  are unusual types of bacteria (Mycoplasma is a type of bacteria without a cell wall and Chlamydias are intracellular bacteria). As the conditions caused by the various agents have different courses and respond to different treatments, the identification of the specific causative pathogen is important.
Atypical pneumonia
Fungal pneumonia
Lobar pneumonia
Dust pneumonia
Viral pneumonia
Bacterial pneumonia
Lipid pneumonia
Lung abscess