Alzheimer’s disease usually starts insidiously and has a progressive course, with an average duration of about 8-10 years from onset to death, but some patients may have a disease duration of 15 years or more. The development of Alzheimer’s disease can be divided into three stages: early, middle and late. Early stage: 1) Mild impairment of language function; 2) Significant memory loss in daily life, especially of recent events; 3) Confusion about time; 4) Disorientation in familiar places; 5) Lack of initiative and loss of motivation; 6) Depression or aggressive behavior; 7) Loss of interest in daily activities and hobbies in life. In the middle stage: 1. becomes more forgetful, especially forgetting recent events and names of people; 2. cannot continue to live independently; 3. cannot perform activities such as cooking, cleaning, or shopping alone; 4. begins to become very dependent; 5. personal self-care ability decreases and requires assistance from others, such as going to the toilet, washing clothes, and dressing; 6. has increasing difficulty speaking; 7. appears to wander aimlessly and other abnormal behaviors; 8. 8. Frequent wandering even in familiar places such as home and residence; 9. Hallucinations. Later stages: 1. inability to eat independently; 2. inability to recognize family members, friends, and familiar objects; 3. marked difficulty in understanding and expressing language; 4. difficulty finding one’s way around the house; 5. difficulty walking; 6. incontinence of bowels and urine; 7. inappropriate behavior in public places; 8. becoming wheelchair-bound or bedridden.