Damage to bodily functions leads to a decline in bodily functions, and the body’s ability to resist infection decreases, and multiorgan insufficiency syndrome in the elderly is a manifestation of decreased infectious ability. Older people due to aging and chronic diseases and other physiological and pathological changes, MODSE clinical performance and young and middle-aged MODS are significantly different, what are the diagnostic signs of decreased resistance to infection? 1, often occurring on the basis of impaired organ function Simple ageing factors can make the elderly organs generally decline in function by 1/3, the chronic diseases suffered by further decline in the function of the affected organs, according to statistics in China MODSE, per capita suffering from 2.4 important chronic diseases, more than 9, these organs once stimulated by the triggering factors, its function will deteriorate sharply, a chain reaction occurs, leading to multi-organ function Failure. Infections and acute attacks of chronic diseases are common triggers Infections, especially pulmonary infections, are often the main trigger (64%-74%), and acute attacks of chronic diseases are also the main trigger, among which cardiovascular and cerebrovascular emergencies are common (9.3%), and others include gastrointestinal bleeding, sepsis, surgery and trauma, nephrotoxic drugs, etc. 3. The order of organ failure is related to the original chronic disease The first organ-free and order is closely related to the degree of impairment of the original organ function, with lung and heart leading the list, followed by brain, kidney, gastrointestinal and liver. 4, clinical manifestations are not parallel, easy to delay diagnosis and treatment MODSE, its clinical manifestations and the degree of damage to the failing organs are not parallel, the pathological changes are serious but the clinical manifestations go more subdued, this is because the body’s immune capacity is reduced, to long-term multiple stimuli (such as low perfusion, chronic inflammation, infection, etc.) has produced a certain tolerance or adaptability. 5, the course of the disease is prolonged, recurrent MOSD in young and middle-aged people in a short period of time (24-72h) almost simultaneous multiple organ failure, rapid onset, rapid regression (1-2 weeks to recover or die). Delayed, sometimes for months or even years, and can be recurrent. 6, the involvement of organs and difficult to completely reverse the elderly patients involved in organs significantly more than young and middle-aged patients, the death rate also increases with the increase in organ failure, as these organ failure occurs more in the aging and chronic diseases, the degree of damage and delayed lasting, it is difficult to completely reverse through treatment. 7, complicated by gastrointestinal bleeding or renal failure high death rate clinically observed to MODSE patients with gastrointestinal hemorrhage and renal failure, the death rate is significantly higher, respectively, 96.3% and 90.5%.