Alzheimer’s disease, also known as dementia (AD for short), occurs mostly in old age and pre-geriatrics, and is a degenerative disease of the central nervous system characterized by progressive cognitive dysfunction and behavioral impairments as symptomatic manifestations. Clinical manifestations include memory impairment, aphasia, dysarthria, dyscognition, impairment of visuospatial ability, impairment of abstract thinking and numeracy, and personality and behavioral changes. Patients may show only very mild memory loss and reduced learning ability in the early stages of the disease, which gradually develops into near-memory loss, often forgetting things done in daily life and commonly used objects, and reduced ability to work, learn new things, and socialize. As the disease progresses, the patient will experience a decline in logical thinking, comprehensive analytical ability, verbal repetition and computational power, and may eventually show emotional indifference, moodiness, loss of speech, inability to complete simple tasks such as eating and dressing, and ultimately may lose the ability to have contact with the outside world. Suspected Alzheimer’s disease requires timely intervention and treatment and is expected to have a better prognosis.