As age increases, the number of diseases suffered by the elderly also increases, and shows a variety of manifestations such as atypical manifestations and many complications. 1. Various diseases usually have their specific symptoms, but the elderly tend to be characterized by non-specific symptoms. For example, elderly patients with myocardial infarction may not have chest pain, but with night sweats, shortness of breath, vomiting, fainting, and toothache as the main manifestations; elderly patients with congestive heart failure may not have shortness of breath, but with psychiatric symptoms, abnormal taste, abdominal distension and abdominal pain. Therefore, very serious diseases may be hidden behind mild symptoms in the elderly. These non-specific symptoms suggest that the patient may be suffering from a disease, but they do not indicate what specific disease is being suffered from, thus making the diagnosis of diseases in the elderly more difficult. For example, when an elderly person suffers from blindness, hemiplegia and other diseases, physical activity is limited, which can make the symptoms of angina pectoris or cardiac insufficiency masked. There is also a common phenomenon that the symptoms of one organ sometimes reflect the disease of another organ, such as pneumonia can show a change in consciousness or anorexia, urinary tract infection can be manifested as unsteady walking or falling to, and so on. 2, asymptomatic patients are many, painless myocardial infarction, no three more and one less typical manifestations of diabetes, asymptomatic peptic ulcer, asymptomatic lacunar cerebral infarction and other diseases. Due to the diminished immune function of the elderly, it is easy to complicate respiratory, biliary and urinary tract infections on the basis of chronic diseases. In the use of broad-spectrum antibiotic therapy, and easy to secondary fungal infections. 3, due to the stability of the internal environment, poor compensatory capacity, as long as the slightest cause can lead to water, electrolyte disorders, the elderly are prone to multiple organ failure. For example, the elderly reduced mobility or bedridden, will cause decreased appetite, reduced serum albumin, which in turn causes decreased immunity. Once infection, trauma, bleeding and other stressful diseases occur, it will rapidly cause multiple organ failure. 4, the elderly due to various reasons lead to long-term bedridden, prone to motor reduction disease. Occurring in the local, can be manifested as contracture, disuse of muscle atrophy, pressure ulcers, thrombosis and embolism, edema, and skin and nail atrophy, etc.; if occurring in the whole body, can be manifested as infectious diseases (crashing pneumonia, urinary tract infections, sepsis), depression, dementia, lethargy, upright low blood pressure, hypoproteinemia, constipation, urinary and fecal incontinence and so on. 5, most of the diseases of the elderly belong to chronic diseases, often insidious onset, slow progress, can be in a considerable period of time without symptoms, can not determine its exact onset time, such as atherosclerosis, senile cataract, diabetes mellitus and osteoporosis and so on. Therefore, regular health checkups for the elderly can help early diagnosis and treatment of diseases. 6, although the onset of geriatric disease is insidious, but with the progress of the disease, organ function gradually develops to the edge of failure, once there is a stress response, organ function will rapidly fail, resulting in deterioration. For example, when elderly patients with coronary artery disease are complicated by pneumonia, if acute left heart failure is induced, the presence of pulmonary stasis will facilitate the growth and reproduction of bacteria, aggravating the lungs and making it difficult to control, thus forming a vicious circle. The most vulnerable parts of the elderly over the age of 75 are the brain, lower urinary tract, cardiovascular and locomotor systems. Falls, reduced activity, psychiatric symptoms, incontinence and loss of ability to live are known as the “five signs of geriatric disease”, and as aging increases, whatever disease occurs, it manifests itself in one or more of the ‘five signs’, the older the more so. Therefore, it has been said that you cannot look at a child as an adult, nor can you look at an older person as an adult.