Pneumonia is one of the most common and important problems affecting the health of the elderly. The incidence of pneumonia increases with age because of the diminished immune system and respiratory defenses, and because of the many underlying diseases that accompany it. The manifestations of pneumonia in the elderly are as follows: 1. atypical symptoms: manifestation of dyspnea without obvious cough, sputum, or chest pain; 2. less pronounced manifestations in the elderly with diminished underlying functions and poor cognitive ability: less prominent manifestations of infection without obvious fever, chills, or muscle aches. Some patients have mainly extra-pulmonary manifestations and atypical pulmonary manifestations.