Medical classification of pneumonia according to pathogen type, disease course and pathomorphology: 1. Classification of pathomorphology: pneumonia is classified into lobar pneumonia, bronchopneumonia, interstitial pneumonia and capillary bronchitis, etc. 2, according to the type of pathogen: including bacterial pneumonia, common bacteria such as Streptococcus pneumoniae, Staphylococcus, Haemophilus influenzae, etc. Viral pneumonia, common viruses such as respiratory syncytial virus, influenza virus, parainfluenza virus, adenovirus, etc. There are also fungal pneumonia, mycoplasma pneumonia, chlamydia pneumonia, etc. The pneumonia is classified according to the course of the disease: acute pneumonia, extended pneumonia and chronic pneumonia, the general course of extended pneumonia up to 1 to 3 months, more than 3 months is chronic pneumonia.