An acute or chronic inflammation of the lungs caused by viruses, bacteria or other microorganisms, or sometimes by physical or chemical irritants.

plural of pneumonia

(medicine) Pneumonia affecting one lung.

Pneumonia affecting both lungs.

(medicine) A bacterial infection of the lungs, characteristically showing inflammation of an entire lobe.

An atypical pneumonia, not caused by the more traditional pathogens, and with relatively mild symptoms.

A form of pneumonia caused by the yeast-like fungus Pneumocystis jirovecii.

(medicine) Pneumonia not caused by one of the pathogens most commonly associated with the disease, such as Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.

plural of atypical pneumonia

(pathology, virology, informal, politically offensive in Mainland China) A form of pneumonia due to infection by a coronavirus (SARS-CoV-2), which is genetically similar to SARS and MERS.