Alzheimer’s disease, also known as Alzheimer’s disease, is a progressive, fatal neurodegenerative disease that is characterized by deteriorating cognitive and memory functions, progressive decline in the ability to perform activities of daily living, and various neuropsychiatric symptoms and behavioral disturbances. So, what causes the diminished ability to perform activities of daily living and behavioral abnormalities in the elderly? Alzheimer’s disease is a group of primary degenerative brain degeneration diseases of unknown etiology. It usually starts in old age, is latent, slow and irreversible, and is clinically characterized by intellectual impairment. The pathological changes are mainly diffuse cortical atrophy, widening of the sulcus gyrus, enlargement of the ventricles, massive reduction of neurons, age spots, neurogenic fiber nodes and other lesions, and significant reduction of choline acetylase and acetylcholine content. Those with the onset of dementia before 65 years of age are often referred to as pre-mortem dementia or progeria, and have a family history of the same disease, with rapid progression and significant temporal and parietal lobe lesions, often with aphasia and disuse. The patient’s brain was found to have extensive neuronal fiber tangles and axonal tangles forming senile plaques after autopsy. The senile plaques contain fragments of necrotic neuronal cells, aluminum, abnormal proteins, and excessive accumulation of beta -amyloid in the brain of patients with Alzheimer’s disease. The gene is located on chromosome 21 due to abnormalities in the pre-amyloid protein causing protein components to leak out of the cell membrane, resulting in neuronal fiber tangles and cell death.