Alzheimer’s disease (AD) is a chronic progressive disease that is increasing in number at the rate of doubling every 20 years, and it is expected that by 2020, the number of dementia patients in China will reach 10.2 million and will become the first country with AD. The onset of AD is insidious and the symptoms are often mild at the beginning, so it is often mistaken as a normal aging phenomenon and not taken seriously by patients’ families. In fact, the prevention and treatment of AD focuses on “early”, that is, early detection, early medical consultation, early diagnosis and early treatment. 1, early identification of dementia symptoms The symptoms of AD patients can be summarized as ABC, i.e. cognitive dysfunction, mental behavior abnormalities, and diminished or even lost ability in daily life. (1) Cognitive dysfunction Memory impairment is a prominent symptom in the early stage of AD. The symptoms include forgetfulness, especially of recent events, such as forgetting things that have just been used, losing daily necessities, forgetting things that have just been said or done, asking for a meal again soon after eating, not being able to remember the names of people or places recently contacted, saying the same things or asking the same questions over and over again. Often misplaces or loses things, forgets to pay for purchases or pays for them several times. Needs to be reminded of everything or relies on “memos”, often forgets to go to important appointments. The housewife forgets to put salt in the stir-fry or puts salt in the stir-fry several times, cooks rice and boils water dry. As the disease progresses, distant memory becomes impaired, and the person cannot recall his or her work experience, life experience, or even his or her age. Déjà vu and old-as-new syndrome may occur, such as meeting strangers and greeting them warmly as if they were relatives, while acquaintances and familiar places feel unfamiliar. Patients may lose the ability to recognize themselves and develop “mirror syndrome”, such as asking “who are you” in the mirror, and have been known to smash the mirror with a fist because they thought a burglar was intruding. Patients may get lost in familiar surroundings, fail to find their own home, or even go to the wrong room or toilet in their own home. There is a general decline in intelligence, including cognitive functions such as comprehension, reasoning, judgment, abstract generalization and calculation. First of all, they have difficulty in calculation and cannot perform complex operations, even addition and subtraction within two digits. Gradually, the thinking ability becomes slow and sluggish, unable to think abstractly and logically, unable to distinguish the similarities and differences between things, unable to analyze and summarize, unable to read the plot of novels and movies, unable to understand other people’s conversations, etc. (2) Mental behavior abnormalities Personality changes often appear in the early stage of the disease. Initially, patients show a lack of initiative, reduced activity, loneliness, difficulty in adapting to new environments, selfishness, reduced interest in the surrounding environment, and lack of enthusiasm for people. Later, the interest becomes narrower, cold to people, even indifferent to relatives, irresponsible, emotionally unstable, easily provoked, angry over trivial matters, reprimanding or cursing, vulgar speech, beating family members, etc. Lack of shame and sense of ethics, behavior in defiance of social norms, unkempt, unhygienic, often picking up rags, hiding dirt and dirt as the treasure of the world, taking other people’s belongings for themselves, fighting for food and drink just like children. When the disease is serious, it can show instinctive activity, public nudity, and even sexual behavior abnormalities. A variety of psychiatric symptoms may occur, including hallucinations, delusions, mistaken identity, depression, mania-like, agitation, aimless wandering, wandering, physical and verbal aggression, shouting, and fecal incontinence. Sleep disorders are quite common, manifesting as sleep inversions, staying awake at night, wandering around, or making purposeless movements, and being drowsy and sleepy during the day. Many psychobehavioral symptoms are based on cognitive impairment, such as delusions of theft due to memory impairment and forgetting where to place objects, or person orientation disorder and not recognizing family members or spouses and believing them to be frauds or impostors. Some symptoms are secondary to personality changes, such as withdrawal, eccentricity, pestering, hiding, and vandalism. (3) Decrease or loss of daily living ability, such as the ability to dress, eat, walk and work, etc. The ability of daily living gradually decreases, and the person is unable to complete or perform familiar work, unable to make continuous complex movements such as brushing teeth correctly with gestures, dressing in the wrong order of inside and outside, front and back, left and right, eating without using chopsticks or spoon, or grasping food with hands or licking food with mouth, and finally losing the ability to live completely. 2. Early treatment of dementia Once the above symptoms are detected, it is important to seek medical attention as soon as possible to slow down the progress of the disease as much as possible. The purpose of dementia treatment is to improve cognitive function; delay or stop the progress of dementia; inhibit and reverse some of the key pathological processes in the early stages of dementia; improve the patient’s ability to perform daily life and improve quality of life; reduce complications and prolong survival; and reduce the caregiver’s burden of care. The treatment of dementia focuses on improving cognitive function and psychobehavioral abnormalities. Commonly used drugs to improve intelligence include cholinesterase inhibitors such as donepezil, galantamine, and stilbestrol A (diacetylpine, harbine); excitatory amino acid antagonist memantine; calcium antagonist nimodipine; ergot alkaloids such as dihydroergotine; pyrrolizidine such as aniracetam; antioxidants such as vitamin E; and ginkgo biloba preparations. Mental behavior abnormalities can be controlled by antipsychotic drugs. In addition, rehabilitation therapy can be helpful. Under the guidance of doctors, appropriate medication should be chosen at different stages of the disease to improve the quality of life and reduce the burden on society and family.