Clinical Definition

Walking pneumonia (atypical pneumonia) is an infectious disease characterized by pulmonary infiltrates. Walking pneumonia is usually clinically milder than other types of pneumonia. The causative agent may vary but is often mycoplasma bacterium. The infection is contagious, and transmission is usually by respiratory droplets from an infected individual.

In Our Own Words

Walking pneumonia is a respiratory infection. It is a type of pneumonia but is usually a milder form of the illness. It is called walking pneumonia because someone may not realize they have the infection due to the mild nature of the disease.

Various types of viruses, fungi and bacteria can lead to atypical pneumonia. One common cause is the bacteria mycoplasma. Mycoplasma pneumonia can develop at any time of the year, but is more common in the late summer months and fall. It is often spread from person to person through droplets from sneezing and coughing.