Walking pneumonia, also called atypical pneumonia, is a milder form of pneumonia that does not usually require hospitalization, according to WebMD. Pneumonia in general is caused by bacteria, viruses, fungi, chemicals and inhaled food. Specifically, walking pneumonia is usually caused by a bacterial infection of the lung called Mycoplasma pneumoniae, which is most common in people under age 40.
The illness is called walking pneumonia because the infected are not usually sick enough to be confined to bed like typical pneumonia patients. Walking pneumonia is contagious, but those infected may feel well enough to go to work, school and other public places, allowing the bacteria to spread. People infected with walking pneumonia begin showing symptoms within 15 to 25 days after infection and are typically infectious for less than 10 days, according to WebMD.
The most common symptoms of walking pneumonia include a violent cough with very little mucous, fever and chills, sore throat, headache, lethargy, and weakness that sticks around for a few days after other symptoms are gone. Walking pneumonia is treated with antibiotics or simple home remedies, such as fluids and rest, if symptoms are mild enough. Those who have had walking pneumonia may have some short-term immunity, and a subsequent case may be milder, according to WebMD.