Patients with dementia exhibit diminished abilities including thinking, memory, comprehension, calculation, language, judgment, orientation, and learning in the waking state, and are partially accompanied by personality changes. “Dementia can be caused by a variety of factors, the most common being neurodegenerative dementia represented by Alzheimer’s disease and vascular dementia that occurs after a stroke. In addition, infections, substance abuse, chronic excessive alcohol consumption, vitamin B12 and folic acid deficiency, hypothyroidism, and uremia can also cause dementia.” Among dementias that occur in old age, Alzheimer’s disease and vascular dementia account for the majority, with the former accounting for 60 to 80 percent and the latter for about 20 percent. ”Recent memory deficits are the earliest clinical manifestation. It starts with occasional forgetfulness, and patients have concurrent mood changes such as anxiety and depression, which manifest as insomnia.” As the condition worsens, the elderly experience frequent recent forgetfulness, mainly in the form of inability to remember scheduled appointments or tasks, inability to remember events that have occurred recently, and forgetting even what has just been said. When the disease progresses further, a significant number of patients develop delusions, most commonly suspicions of property theft, suspicions that they have various illnesses, that an outsider or even their children are trying to harm them, and that their spouse is cheating on them. Patients then develop disorientation, cannot distinguish between day and night, do not recognize their homes when they go out, easily get lost or even become so severe that they do not know their own identity or that of others. Another early symptom of Alzheimer’s disease is a reduced ability to learn new knowledge and acquire new skills, and the tendency to feel tired, frustrated and irritated in the face of new things and operations. For example, when a new appliance is added to the home, some elderly people are slow to learn and cannot remember how to operate it, so they stubbornly refuse to use it or get angry at their children. In terms of emotions, the patient will slowly become indifferent, sluggish, lack of energy, easily fatigued, lose enthusiasm for work, lose interest in activities they used to enjoy, sometimes cry easily, laugh easily and get angry easily, and even make some bad jokes that are not appropriate for the time. Many patients do not pay as much attention to clothing and grooming as before, becoming slovenly, untidy and unkempt. Some people become suspicious, stubborn and calculating.