If you're seeing this message, it means we're having trouble loading external resources for Khan Academy.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

What is pneumonia?

VIDEO 10:23 minutes
Pneumonia is a medical condition where lung tissue becomes inflamed, usually caused by a virus or bacteria. Learn how shortness of breath, cough, and fever are common symptoms of this condition and why they occur in pneumonia.

Streptococcus pneumoniae and flu vaccines

VIDEO 6:47 minutes
Why do we need a new flu vaccine every year? Learn about the pneumonia and flu vaccines and how they help your body fight off infection.

Pulmonary abscess

VIDEO 6:08 minutes
Pulmonary abscesses occur when part of the lung tissue dies (caused by damage or infection) and gets trapped in a layer of hard tissue in the lung. Learn what causes abscesses, how they are diagnosed, and how health professionals treat ...

Pneumonia vs. pneumonitis

VIDEO 8:55 minutes
Pneumonitis is a term used to describe inflammation of the lung tissues without the presence of an infection, whereas pneumonia is inflammation caused by an infection. Learn what the symptoms of pneumonitis are, and why pneumonitis is more ...