Definition of Mycoplasma pneumonia:

Mycoplasma pneumonia is an infection of the lungs caused by Mycoplasma pneumoniae (M. pneumoniae).

Causes, incidence, and risk factors:

M. pneumoniae is a common cause of mild pneumonia that usually affects people younger than 40. Various studies suggest that it causes 15-50% of all pneumonia in adults and an even higher percentage of pneumonia in school-aged children.

People at highest risk for mycoplasma pneumonia include those living or working in crowded areas such as schools and homeless shelters, although many people who contract mycoplasma pneumonia have no identifiable risk factor.