What is walking pneumonia?

Walking pneumonia: Generally a term which suggests that the patient can be treated as an outpatient rather than having to be hospitalized. It is a poor term to use because it neither defines the cause of the infection, the mechanism by which it occurred, or the type of therapy necessary.

Atypical pneumonia.: "Walking pneumonia" is an older term for what we now call atypical pneumonia, that which is caused bacteria that we don't typically find in cases of pneumonia. These bacteria tend to cause milder versions of pneumonia, so you feel sick but not REALLY SICK, so you tend to "walk" around with your pneumonia not realizing you actually have pneumonia that requires treatment.