World Alzheimer’s Day is celebrated on September 21st in order to raise awareness of Alzheimer’s disease on a wider scale. Dementia, also known as Alzheimer’s disease, is a serious intellectual disability. The vast majority of people with Alzheimer’s disease do not seek medical treatment in a timely manner, which puts a serious burden on their families and households. What are the early symptoms of Alzheimer’s disease? How to prevent Alzheimer’s disease? It is understood that Alzheimer’s disease (AD) is a progressive neurodegenerative disease with insidious onset. Clinically, it is characterized by comprehensive dementia manifestations such as memory impairment, aphasia, apraxia, dysarthria, dyscognition, visuospatial skill impairment, executive function impairment, and personality and behavioral changes, and the cause of the disease is still unknown. Those who develop the disease before the age of 65 are called early-onset dementia, while those who develop the disease after the age of 65 are called senile dementia. Alzheimer’s disease may be a heterogeneous group of diseases that develop in response to a variety of factors (including biological and psychosocial factors). From the current research, there are more than 30 possible factors and hypotheses for the disease, such as family history, female gender, head trauma, low education level, thyroid disease, high or low maternal reproductive age, and viral infections.