Dementia is a more severe and persistent syndrome of cognitive impairment. It is clinically characterized by slow onset diminished intelligence with varying degrees of personality changes but no impairment of consciousness. Dementia usually starts unknowingly and develops slowly. By the time symptoms become apparent the best time for treatment has been missed, so it is important to recognize the early symptoms of dementia. Early signs of dementia are: 1. Forgetfulness: Everyone forgets things, but normal people are able to recall things afterwards or after reminders. The elderly with dementia often forget things and can never remember them afterwards, and may ask the same questions over and over again. 2. Forgetting: The elderly may forget to bring food to the table after cooking, forget to bring keys when they go out, forget to take medication, etc. 3. Words do not make sense: The elderly often get stuck in their initial speech, unable to find the right words to express their meaning, or say the wrong thing, which can be easily misunderstood. 4. Confusion about time and place: The elderly may confuse the order of events, not know the current date, or get lost in a familiar place. 5.Decreased judgment: When emergencies, unexpected events and complex tasks occur, they are unable to make accurate judgments and handle them. Simply put, the elderly are not as smart and capable as before. 6.Loss of abstract thinking ability: The elderly cannot make general analysis, for example, they do not know that oranges and bananas are both fruits. 7.Randomly placing things: The elderly often put things in inappropriate places, such as putting the iron in the refrigerator, or putting the watch in the cookie box, or treasuring many scraps as treasures, and persuasion has no effect. 8, temper and behavior change unpredictably: people will have some emotional changes when they get old, but the behavior and emotions of the elderly with dementia may change dramatically, from a calm state to a tearful state in just a few minutes, unable to help themselves, or shoot up in anger. 9, personality changes: the elderly may undergo dramatic and unreasonable changes in personality, such as inexplicable fear, or suspicious, suspicious of others, and so on, and the original character is very different. 10. Loss of initiative: they often become lazier than before, unwilling to participate in any activities, even those they used to enjoy, and unenthusiastic towards people. In short, when an elderly person shows one or several of the above-mentioned manifestations, he or she needs to be alert to dementia.