The development of Alzheimer’s disease may not be very serious when it first appears. But as it is not controlled with good treatment, Alzheimer’s will progress further. The result of this is that Alzheimer’s will have different stages. Clinically, Alzheimer’s is divided into three stages, each of which has different symptoms. And the response of dementia is getting more and more severe. So, what are the symptoms of each of the three stages of dementia? The first stage is the amnesia stage. For example, at the beginning, the person forgets what he or she has said, done or important appointments, and gradually forgets even distant things. At the same time, the ability to think and analyze, judgment, visual-spatial discrimination, and calculation ability are also reduced. It is still possible to keep the familiar work of the past. The second stage, the three stages of Alzheimer’s disease are analyzed. Symptoms worsen in the confusion stage. It is also difficult to dress, or to wear pants as clothes. Does not recognize the faces of friends or relatives and cannot remember their names, and cannot talk to others, although sometimes talking to oneself. The most striking manifestation is a marked increase in visual-spatial discrimination and the tendency to get lost. The third stage, extreme dementia. The person with Alzheimer’s disease enters a state of total decline and cannot take care of himself/herself, such as eating, dressing, bathing, and being incontinent. Explanation of the three stages of Alzheimer’s disease. The symptoms of Alzheimer’s disease are aggravated by the process, so it will be very convenient to treat Alzheimer’s disease if action can be taken in the first stage. Therefore, we hope that our families and friends can start treating patients in the first stage of Alzheimer’s disease.