Alzheimer’s disease (also known as senile dementia) is the most common cause. It is a primary degenerative disease of the brain with a slow onset and progressive course. Patients mainly show a decline in memory, intelligence (including understanding, reasoning and judgment, abstract generalization and calculation, etc.), language, operation and personality, and other cognitive functions, and some also show psychiatric symptoms. According to the most conservative estimates there are at least 6 million people with Alzheimer’s disease in China, and the prevalence of the disease in people over 65 is 5%. It is estimated that by 2015, there will be 135 million people over the age of 65, so the number of “dementia” patients will reach 6.75 million. Alzheimer’s disease was once seen as the fourth leading health killer, but as a quiet “killer”, its early symptoms are often overlooked as the “old fogeys” of the elderly. Early detection and intervention are the most effective measures to delay dementia in old age. The following points can help in the early identification and detection of Alzheimer’s disease: 1. Time and place confusion: In the early stages of Alzheimer’s disease, the patient often gets lost, even on the road he or she used to be familiar with, not knowing where he or she is or how to get back to his or her home. Some do not know the year, month, date, or even what season it was, etc. 2. Emotional or behavioral changes: The early emotional and behavioral changes of Alzheimer’s patients are more obvious. In a quiet environment, the patient may cry inexplicably without any stimulation or reason, and some may even become very angry, making noise, cursing, and damaging things. 3. Decreased judgment: In the early stages of Alzheimer’s disease, the patient will often partially or completely forget what he or she is doing, and the quality of daily familiar chores decreases significantly, such as forgetting to choose the food, forgetting to put salt or other seasonings, or even forgetting to put the ceasefire, resulting in damage to the property. Daily dress may also be less coordinated and appropriate than before, such as wearing several shirts or short sleeves at the same time, or wearing underwear on the outside of a sweater, or dressing out of season, etc. 4.Abstract thinking disorder: In the early stage of Alzheimer’s disease, patients may have difficulty with simple arithmetic, such as going to the market and shopping, which they were familiar with, and making accurate change. 5. Personality change: The early personality change of Alzheimer’s patients is often obvious, they will become extremely sensitive and suspicious, originally he or she put things away by himself or herself, but afterwards forget where he or she put them, want to look for them but can not find them, so they suspect that people who often contact him or her have stolen them, and become angry with them. Some of them are very fearful, always feel that something bad is going to happen, threatening his/her own safety and the safety of his/her relatives, staying by the phone all day, waiting for a call from relatives, checking the phone repeatedly when there is no call, always saying whether the phone is broken, etc. Personality will become more and more irritable, stubborn, often over trivial matters and quarrel, quarrel. 6. Loss of initiative: In the early stages of Alzheimer’s disease, patients often lose their initiative and become extremely passive, needing constant prompting or supervision to participate in some activities.