Pneumonia, a potentially serious infection within one or both lungs, is often caused by bacteria such as Streptococcus pneumoniae. However, it can also be caused by viruses, fungi, or parasites.
Common symptoms of pneumonia include:
- A cough that produces green or yellow phlegm
- Chest pain when breathing or coughing
- A rapid heart rate and breathing rate
- Fever (temperature greater than 100.5ºF or 38ºC) or chills.
Symptoms may range in severity from mild to severe. The exact amount of time that pneumonia lasts will vary. It usually takes three to five days before a person starts to feel better; it can take three weeks or more before a person feels well enough to go back to his or her normal routines. Symptoms such as fatigue and mild cough can last for a month or more.
(For more detailed information on this condition, including the difference between walking pneumonia and regular pneumonia, click Pneumonia.)