The examination of dementia mainly includes the following aspects.

First, it is to determine whether the patient has cognitive impairment, because in the early stages of dementia this impairment is often mild, primarily in recent memory, with other aspects not yet obvious. Early screening can use some cognitive evaluation scales, such as the Mini-Mental State Examination or the Montreal Cognitive Assessment, chosen according to the patient's cultural level.

Second, imaging examination, commonly using brain MRI, can reveal significant signs of dementia such as deepened brain sulci, narrowed gyri, and widened lateral fissures, indicating brain atrophy.

Third, genetic testing for the APOE gene, which may be related to dementia. Possession of this gene may increase the likelihood of developing dementia in the future, serving as an auxiliary diagnostic measure.