Alzheimer’s disease is a progressive process and can be roughly divided into early, middle and late stages according to the severity of the disease. The early symptoms of Alzheimer’s disease are mainly the loss of memory in the case of clear consciousness and the impairment of thinking and reasoning ability in daily life, such as forgetting where to put something and thinking it was stolen, forgetting home address and getting lost. In the early stages of the disease, the patient is able to take care of himself/herself, but as the disease worsens, the main speech becomes blunt and dull, and there are language disorders (e.g., empty words, unable to name individual objects), behavioral disorders, and a reduced range of activities. Patients are unable to learn new knowledge and skills, or to perform abstract thinking and calculation, and may appear emotionally indifferent, depressed or frustrated, but they can take care of themselves in daily life. Second, the middle stage ( mental disorder ) With the progressive aggravation of the disease, many patients will go to the hospital. In this stage, in addition to memory and intelligence decline, there is also distraction, forgetting to eat without being fed; in severe dementia, there is loss of the concept of time and place, increased difficulty in calculation, inability to express oneself verbally (aphasia), clumsy movements and inability to use tools (disuse). Mentally, he/she may be foggy, expressionless, hallucinating, such as hearing someone talking to him/her outside the window, and dependent on others for care. The patient is prone to tantrums, shouting, aggressive behavior, wandering blindly, binge eating, playing with fire, getting lost, making noises in the middle of the night or making strange noises, depression, lazy life, and gradually the patient becomes more blurred about the surrounding things. All the above symptoms vary greatly among individuals. Patients in this stage cannot take care of themselves and need long-term supervision, so the burden of caregivers is high, so patients in this stage should be sent to geriatric hospitals or nursing hospitals for care if possible. In the late stage (severe dementia), the patient loses the ability to recognize friends and relatives or can only recognize one or two people closest to them. Patients completely lose the ability to take care of themselves in daily life, caregiving becomes increasingly difficult and requires assistance, and patients often end up dying from various complications ( such as lung infections, bed sores, fractures, etc.). In addition, many scholars have developed more detailed grading scales for this disease (dementia), and the more commonly used one is the Clinical Dementia Rating Scale (CDR).