Alzheimer’s disease, medically known as Alzheimer’s disease, is a combination of cognitive and non-cognitive symptoms with persistent and slow memory impairment as the main core manifestation, which is prevalent in older people over 60 or 65 years of age, and before 60 years of age, it is known as early senile dementia. The main manifestations are as follows: I. Cognitive Symptoms Cognitive symptoms are the impairment of executive functions such as thinking and logic, memory and attention. 1.Impairment of near memory and orientation: the core manifestation is the impairment of near memory, such as the forgetting of things earlier in the day or the day before, which is gradually aggravated, and the problems of orientation, getting lost, etc., which are more prominent in the middle and late stages or the serious progress stage. 2.Speech dysfunction: naming aphasia, inability to name familiar and commonly used things, also manifested as repetitive, stereotyped and persistent speech. 3.Thinking logic disorder: it is mainly manifested as poor comprehension of new things and new things, and there is now a decline in the ability to understand and master some things that can be mastered by people of the same age or that used to be easily understood. The rationality and rigor of thinking are poor, and even the basic logical judgment ability is affected. 4, executive dysfunction: mainly attention disorder, attention narrowing, attention dispersion, attention switching and other difficulties, in addition, some spatio-temporal perceptual ability is impaired, such as poor drawing experiments (inaccurate drawing of clocks, many errors), basic spatial orientation disorders and so on. 5, other neurological symptoms: such as fine motor, large limb movement and ataxia, etc., muscle and muscle strength abnormalities, dizziness, headache and perceptual symptoms are also more common. Second, non-cognitive symptoms is often referred to as mental disorders, the main manifestations: 1, hallucinations and delusions: often hear or see someone and their own conversation, so in the house talking to themselves or dancing; some suspected for no apparent reason that some people are stealing their own things, or to harm themselves, feel insecure, afraid to avoid. Some sensitive and suspicious, see family members or outsiders talk, think they are talking bad about themselves, so very angry. 2, mood and emotional symptoms: mainly for depression or anxiety response, some appear to lose their temper for no reason, such as mania-like performance, severe depression or negative self-inflicted suicidal behavior, very dangerous, anxiety, restlessness, such as sitting on pins and needles, tossing and turning, just can not quiet down. 3, sleep disorders: mainly for insomnia or sleepy performance, insomniacs have difficulty falling asleep, do not sleep at night, walking around, daytime lethargy 4, behavioral disorders: repetitive, stereotypical behaviors are common, some old people like to collect shredded paper for no apparent reason, useless small things or garbage, in the home around the storage, and can not be persuaded; impulsive aggression is also more common. 5, personality change: character becomes selfish, cold, childish and even vicious and other incomprehensible. If the above manifestations appear slowly and gradually worsen, you should first need to check the cranial nuclear magnetism to observe whether there is any brain imaging abnormality, and secondly, neuropsychological examination is also necessary to complete for clinical evaluation and screening.