Pneumonia Diagram Pneumonia occurs when the lining of the lungs becomes inflamed because of a viral, bacterial or fungal infection. Prompt treatment is essential, and here are some signs to watch for:

  • Cough with mucus that is green or yellow, or coughing up blood.
  • Chest pain that worsens while coughing.
  • Difficulty breathing, including shortness of breath or very rapid breathing.
  • Fever with chills, headache, disorientation (especially in seniors), and fatigue.
  • Excessive sweating with clammy skin.