Pneumonia is an inflammation of the lung, usually caused by infection.
In the process the patient develops symptoms such as chills, fever, cough, and general malaise. Pneumonia can be caused by almost any type of organism, although a few specific viruses and bacteria are responsible for most cases, and can occur at any age. One of the great medical advances has been the development of antibiotics for treating some of the pneumonias. Penicillin, erythromycin, and tetracycline are among the most useful. Despite this miracle group of drugs pneumonia remains a very important problem.