Infection that inflames air sacs in one or both lungs, which may fill with fluid. With pneumonia, the air sacs may fill with fluid or pus. The infection can be life-threatening to anyone, but particularly to infants, children, and people over 65.
Symptoms include a cough with phlegm or pus, fever, chills, and difficulty breathing. Antibiotics can treat many forms of pneumonia. Some forms of pneumonia can be prevented by vaccines.

Symptoms of Pneumonia:

Symptoms can vary depending on what’s causing your pneumonia, your age, and your overall health. They usually develop over several days.

Common pneumonia symptoms include:

Chest pain when you breathe or cough
Cough that produces phlegm or mucus
Fatigue and loss of appetite
Fever, sweating, and chills
Nausea, vomiting, and diarrhea
Shortness of breath
Along with these symptoms, older adults and people with weak immune systems might be confused or have changes in mental awareness, or they might have a lower-than-usual body temperature.