What’s the Difference Between Alzheimer’s Disease and Dementia?

The terms Alzheimer’s disease and dementia are often used interchangeably. A helpful way to think about the difference is this:

Dementia is the category; Alzheimer’s disease is one diagnosis within that category.

Dementia is an umbrella term—not a specific disease. It describes a syndrome of cognitive decline that interferes with daily functioning. Dementia can affect memory, language, problem-solving, judgment, and visuospatial abilities. There are many causes of dementia, including Alzheimer’s disease, vascular disease, Lewy body disease, frontotemporal degeneration, and other medical or neurological conditions.

The "dementia umbrella" visualizes the fact that dementia is an umbrella term. "Dementia" is a broad category with many different causes/types (as listed in the raindrops).

Alzheimer’s disease is the most common cause of dementia. It is a progressive neurodegenerative disease characterized by changes in the brain, including abnormal amyloid plaques and tau tangles. Alzheimer’s disease typically begins with gradual memory loss—especially difficulty learning new information—and later affects other cognitive abilities and daily functioning over time.

Not all dementia is Alzheimer’s disease.

A comprehensive neuropsychological evaluation helps clarify whether cognitive symptoms meet criteria for dementia and whether the pattern of strengths and weaknesses is most consistent with Alzheimer’s disease or another condition. Identifying the underlying cause is important because progression, management strategies, and treatment options can differ.