Alzheimer’s disease, also known as Alzheimer’s disease, lasts about 5-10 years, with a few patients surviving for 10 years or more. Alzheimer’s disease is the most common type of dementia in old age, accounting for about 50-70% of dementia in old age. With the increasing understanding of Alzheimer’s disease, it is now believed that Alzheimer’s disease is preceded by an extremely important pre-dementia stage, which may have pathophysiologic changes of Alzheimer’s disease but no or only mild clinical symptoms, and which is characterized by a predominantly generalized dementia. Alzheimer’s disease may be a heterogeneous group of diseases, in the role of a variety of factors, the onset of slow or insidious, mostly in patients over 70 years old, a few patients in the disease factors, stimulation induced. Patients with Alzheimer’s disease mostly die from serious complications such as pulmonary infections, urinary tract infections and pressure ulcers, so it should attract clinical attention.