Pneumonia (or pneumonia) is an infection of the lungs caused by different germs such as bacteria, viruses and fungi that spread their microorganisms inside the alveoli (the branches where the exchange of oxygen between inhaled air is made and blood in the lungs), through the nose, pharynx or via blood. This causes inflammation with lung damage, which has highly variable symptoms. In typical pneumonia highlights cough with purulent sputum, sometimes with blood or chest pain, and fever with chills. Calls on atypical pneumonia symptoms are less alarming grade fever, malaise, muscle and joint pain, fatigue, headache, dry cough without expectoration, and chest pain less intense. The severity and treatment of this disease will be determined by the extent of the affected lung, the type of germ that produced, age and previous medical history. The treatment is done in most cases without hospitalization, with oral antibiotics, and only applicable to income in cases where the patient does not respond to initial treatment or present other diseases or pleural effusion.