Pneumonia is inflammation and often infection of the lungs. Although some forms of pneumonia are mild and don't require medical treatment, other forms of the disease can be severe and need prompt medical intervention. Statistics indicate that over 3 million people in the United States are diagnosed with pneumonia each year, and many of them require hospitalization. When pneumonia is caused by infectious agents, the disease is very contagious and it can be easily transmitted through sneezing, cough or physical contact. Therefore, many patients are not hospitalized for the seriousness of their disease, but to prevent them from spreading pneumonia to other people.