Pneumoniais an infection of the lungs by a virus, bacterium, or fungus.
This article covers the causes, types, symptoms, and treatment of atypical pneumonia.
Symptoms typically include:
Signs usually develop five to 14 days after infection and death is extremely rare.

Oleg Breslavtsev / Getty Images
Signs will typically show two to 10 days after exposure to the bacteria.
It may take a month, or more, for your symptoms of atypical pneumonia to go completely away.
The severity of atypical pneumonia can range from mild to life-threatening.
Summary
Atypical pneumonia is a common bacterial infection of the lungs.
It is called atypical due to differences in its detection and clinical presentation compared to other forms of pneumonia.
A Word From Verywell
Atypical pneumonia is quite common, but it rarely leads to hospitalization.
In fact, most people enjoy a full recovery in a few weeks.
Centers for Disease Control and Prevention.Atypical pneumonia.
Centers for Disease Control and Prevention.Psittacosis.
Centers for Disease Control and Prevention.Legionnaires disease.
Bajantri B, Venkatram S, Diaz-Fuentes G.Mycoplasma pneumoniae : a potentially severe infection.Journal of Clinical Medicine Research.
2018;10(7):535-544. doi:10.14740/jocmr3421w
American Lung Association.What is walking pneumonia?