Pneumonia is an infection that inflames the air sacs in one or both lungs. The air sacs may fill with fluid or pus (purulent material), causing cough with phlegm or pus, fever, chills, and difficulty breathing. A variety of organisms, including bacteria, viruses and fungi, can cause pneumonia . Pneumonia is a lung infection affecting the air sacs that makes it difficult to breathe. Learn what causes this condition, how to treat it, and more. Pneumonia is an infection that inflames the air sacs of the lungs and makes it hard to breathe. Learn about the types, stages, symptoms , causes, diagnosis, treatment, and prevention of pneumonia . Pneumonia is an infection in one or both of the lungs. Symptoms of pneumonia vary to mild to severe. Read about the signs of pneumonia .
