The symptoms of pneumonia are similar to the symptoms of a severe cold or influenza (flu). The similarity of symptoms results in pneumonia being difficult to recognize, especially in people who have already been diagnosed with the flu. The symptoms of pneumonia also differ depending on the strength of the immune system and the cause of the pneumonia. Symptoms can begin to appear from several hours to a few days after the initial infection.

Most types of pneumonia may produce the following signs and symptoms:

• Persistent cough
  
  
• Green or rust-colored mucus (sputum)
  
  
• Fever with shaking chills
  
  
• Sharp pain in the chest while breathing deeply or coughing
  
  
• Rapid breathing
  
  
• Shortness of breath
  
  
• Blue tinge to lips and nail beds
  
  
• A rattling or crackling sound from the lungs (rales) when listened to through a stethoscope

In addition, other types of pneumonia may produce the following symptoms:

• Headache
  
  
• Fatigue (sometimes lasting a long time after other symptoms disappear)
  
  
• Loss of appetite
  
  
• Confusion

Pneumonia is particularly difficult to spot in infants and children, who may not display prominent symptoms. Pneumonia could be suspected in infants and children who show the following symptoms:

• Rapid breathing
  
  
• Grunting sound
  
  
• Fever
  
  
• Lack of appetite
  
  
• Abdominal pain
  
  
• Vomiting