Early manifestations of Alzheimer’s disease mainly include: 1. cognitive decline: when meeting an acquaintance on the road, it appears that the person cannot remember who the other person is for a short period of time; 2. memory decline: when going out, the door has been locked and suddenly does not remember whether the door is locked or not and needs to go back to confirm; 3. calculation decline: when going out to buy groceries, it cannot calculate how much money to pay or how much money to make change. It is recommended to take the patient to the doctor promptly when the above early symptoms appear and treat them as early as possible to avoid aggravation of brain infarction, brain hemorrhage, vascular dementia and other diseases.