Generally, those at greatest risk for serious complications from pneumonia have a weaker immune system or a condition or lifestyle factor that affects their lungs. Pneumonia is an infection of the ...

Pneumonia is an infection of one or both lungs which affects alveoli, the tiny sacs found in clusters at the end of the branching structure of airways (respiratory tree) that supply air to the lungs.

Lindsay Curtis is a health & medical writer in South Florida. She worked as a communications professional for health nonprofits and the University of Toronto’s Faculty of Medicine and Faculty of ...