Pneumonia is an inflammatory condition of the lung affecting primarily the tiny air sacs known as alveoli. It can be caused by various infectious agents, including bacteria, viruses, fungi, or parasites. Pneumonia can range in severity from mild to life-threatening and is a significant cause of illness and death worldwide.


  • Bacterial Pneumonia: Common bacteria include Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus.
  • Viral Pneumonia: Influenza viruses, respiratory syncytial virus (RSV), and adenoviruses are common viral causes.
  • Fungal Pneumonia: Fungal pneumonia is less common and often affects individuals with weakened immune systems. Examples include Histoplasma and Pneumocystis jirovecii.
  • Aspiration Pneumonia: Caused by inhaling food, saliva, gastric acid, or other substances into the lungs, often seen in individuals with impaired swallowing.


  • Cough, often with phlegm
  • Shortness of breath
  • Chest pain that may worsen with breathing or coughing
  • Fever and chills
  • Fatigue
  • Sweating
  • Bluish tint to lips or nails (indicating a lack of oxygen)
  • Confusion (especially in older adults)
  • Nausea or vomiting


  • Vaccination: Vaccines are available for certain bacterial and viral causes of pneumonia, such as the pneumococcal vaccine and the influenza vaccine.
  • Good Hygiene Practices: Regular handwashing, covering mouth and nose when coughing or sneezing, and avoiding close contact with sick individuals.
  • Healthy Lifestyle: Maintaining a healthy lifestyle, including a balanced diet, regular exercise, and not smoking, can contribute to overall respiratory health.