Pneumonia is swelling (inflammation) of the tissue in one or both of the lungs. It's usually caused by an infection – most commonly, bacteria and viruses, which are both contagious.
The germs that can cause pneumonia are usually breathed in. People often have small amounts of germs in their nose and throat that can be passed on through:
You can help prevent the spread of a pneumonia by taking some simple hygiene precautions.
There is a vaccine that protects against Streptococcus pneumoniae, which is the most common cause of bacterial pneumonia.
Vaccination is recommended for:
Read more about pneumonia.
Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.