1. Memory loss: from the initial occasional forgetfulness gradually develops into frequent forgetfulness, from forgetting near events and progressing to distant events, from forgetting details of events and involving the events themselves. Immediate recollection is severely impaired, and the magnitude of temporal memory is shortened by the inability to recall events that occurred hours or even minutes ago. Eventually, it can be so severe that even the name, birthday and family size are completely forgotten as if the person was living in childhood, and is often accompanied by reduced calculation power. 2. Impairment of daily functions: Along with memory deficits, orientation disorders may occur. For example, after leaving home, the patient does not know the way home; after going to the toilet, the patient cannot find the bed he slept in, etc. Difficulties in association, reduced comprehension, and poor judgment. At first, the disorder is characterized by a lack of planning and creativity in work, and then the disorder can’t even complete the work that was familiar. For example, a famous chef can not master the fire and the use of spices, cooked dishes are either raw or burnt, either light or salty, can not be imported. In severe cases, they cannot even understand what others are saying, and when they are asked to undress, they open their mouths, and when they are asked to reach out, they stand still for a long time. 3, personality change: personality gradually change, become selfish, high irritability, due to memory loss will also appear suspicious of being victimized, claiming that their things are often stolen by others (the actual place to put things forgotten), put things indiscriminately, busy, do not know what to do, love to hide waste, as treasures, fear of theft, do not pay attention to personal hygiene habits, dirty clothes do not wash, do not rinse in the morning, sometimes appear to be unreasonable and obstruct Sometimes there is a disobedience and public order behavior, affecting the security. 4, emotional disorders at first, the emotions can be more childish, or child-like euphoria, emotional irritability. Subsequently, the expression is dull, emotional retardation. 5, focal symptoms in the course of the disease, may occasionally appear focal symptoms. For example, the earliest and most frequent damage to the neocortical area is naming aphasia, but there may also be other forms of aphasia, as well as various kinds of loss of use, loss of recognition, loss of calculation, and eventually total loss of cognitive ability. 6, appearance changes Alzheimer’s patients with aging appearance, often appear old, full of white hair, teeth fall mouth deflated, corneal has an age ring. Pupil response to light is occasionally dull. The patient may also have a dull physiological reflex, bending of the body, unstable walking, staggering gait, weight loss, muscle wasting atrophy, involuntary head shaking, slurred speech, salivation, finger tremors and difficulty in writing. 7. Laboratory tests: CT scan or MRI often shows different degrees of ventricular enlargement and cortical atrophy, and widening of the cerebral sulcus. EEG shows non-specific diffuse slow waves, slowed alpha wave rhythm and low amplitude; in severe cases, spike waves of 0.5 c/s may be issued bilaterally. Cerebral hemogram shows a decrease in local cerebral blood flow in the cerebral cortex and a decrease in cerebral oxygen metabolic rate. If there is a high suspicion of dementia with the above manifestations, immediate psychiatric consultation is recommended to receive regular treatment.