Pneumonia is an infection of the lungs that can be caused by bacteria, viruses, or fungi. Symptoms include shortness of breath, cough, fever, and chest pain. While pneumonia can often be treated with antibiotics prescribed by a doctor, late detection can lead to severe complications or death. Diagnosis involves listening to the lungs and may also include x-rays, blood tests, or scans. Mild cases are usually treated at home with rest, fluids, and antibiotics when needed.