The causes of dementia in the elderly are not currently completely clear. Dementia in the elderly is mainly divided into familial and sporadic types. Familial dementia shows autosomal dominant inheritance, which is caused by a gene mutation on chromosome 21 leading to the accumulation of some toxins, resulting in the death of neurons and causing dementia fundamentally due to genetic mutations. However, most cases of dementia are sporadic and do not have a clear family history. The mechanisms and reasons for disease onset are not particularly clear. Some believe that abnormalities in cerebral vascular function may lead to neuronal cell functional disorders, resulting in decreased ability to clear certain cell toxins, thus leading to neuronal apoptosis and death, and consequently impaired cognitive functions. In addition, factors such as oxidative stress, inflammatory mechanisms, excessive fatigue, and emergency stress may also cause cell death. Overall, the causes of dementia in the elderly are not particularly clear.