Pneumonia
Pneumonia is an infection in your lungs caused by bacteria, viruses or fungi. Pneumonia causes your lung tissue to swell (inflammation) and can cause fluid or pus in your lungs. Bacterial pneumonia is usually more severe than viral pneumonia, which often resolves on its own.
Pneumonia can affect one or both lungs. Pneumonia in both of your lungs is called bilateral or double pneumonia.
What’s the difference between viral and bacterial pneumonia?
While all pneumonia is inflammation caused by an infection in your lungs, you may have different symptoms depending on whether the root cause is a virus, bacteria or fungi.
Bacterial pneumonia tends to be more common and more severe than viral pneumonia. It’s more likely to require a hospital stay. Providers treat bacterial pneumonia with antibiotics. Viral pneumonia causes flu-like symptoms and is more likely to resolve on its own. You usually don’t need specific treatment for viral pneumonia.
What are the types of pneumonia?
We categorize pneumonia by which pathogen (virus, bacteria or fungi) caused it and how you got it — community-acquired, hospital-acquired or ventilator-associated pneumonia.