How is severe pneumonia caused in the elderly?

The causes of severe pneumonia in the elderly are the same as those in other young people. The main causes are: first, bacterial factors, such as Klebsiella pneumoniae, Staphylococcus aureus, Acinetobacter baumannii, etc. Second, viral pneumonia, such as influenza virus and other viruses that cause lung damage. Third, fungal infections, such as Candida, Aspergillus, and Pneumocystis. Fourth, other atypical pathogens, mainly including mycoplasma, chlamydia. Then why the elderly are more likely to show severe pneumonia, normally related to several aspects, the first is too old, normally more than 65 years old, more likely to show severe pneumonia, at the same time whether there are underlying diseases, including diabetes and chronic heart disease, chronic lung disease, chronic liver disease, chronic kidney disease, etc., these may promote the patient's inflammation is not controlled, and then show induced severe pneumonia.