Alzheimer's disease

noun

Alz·​hei·​mer's disease ˈälts-ˌhī-mərz-  ˈalts-  ˈȯlts- 

variants or less commonly Alzheimer disease

ˈälts-ˌhī-mər- 

ˈalts-, 

ˈȯlts-

or Alzheimer's

: a degenerative brain disease of unknown cause that is the most common form of dementia, that usually starts in late middle age or in old age, that results in progressive memory loss, impaired thinking, disorientation, and changes in personality and mood, and that is marked histologically by the degeneration of brain neurons especially in the cerebral cortex and by the presence of neurofibrillary tangles and plaques containing beta-amyloid

Behavioral problems, such as mood swings and agitation, may also be a part of the progression of Alzheimer's disease.

—Allan Perel

… the ability to differentiate normal aging-related memory changes from the impairments associated with dementia, including Alzheimer disease …

—C. Munro Cullum

… researchers in California have created mice carrying the gene for beta-amyloid protein, the principal component of the plaques riddling the brains of people with Alzheimer's.

—Charlene Crabb

Note: Alzheimer's is often used before another noun.

Alzheimer's patients

—abbreviation AD

Examples of Alzheimer's disease in a Sentence

Recent Examples on the Web

Stewart died Wednesday at his Los Angeles home, surrounded by family and friends and cared for by his wife, Sunny, following a battle with Alzheimer's disease and Lewy body dementia, the statement said. — Brittany Miller , Brie Stimson, FOXNews.com, 29 Oct. 2026

The 44-year-old Connecticut resident and her two siblings help look after their mother, who has Alzheimer's disease and requires around-the-clock supervision. — Megan Cerullo, CBS News, 28 Oct. 2026

Sleep has been shown to play an important role in clearing waste products linked to impaired brain function and Alzheimer's disease from the brain, according to the NIH. — Ava Tsapatsaris, ABC News, 28 Sep. 2026

While Alzheimer's disease typically affects memory first, FTD initially affects areas of the brain associated with behavior, personality and language, according to the Association for Frontotemporal Degeneration. — Sameen Chaudhry, USA Today, 9 Sep. 2026

Word History

Etymology

Alois Alzheimer †1915 German physician

First Known Use

1911, in the meaning defined above

Rhymes for Alzheimer's disease

• ferromanganese
• mephistopheles
• abcs
• absentees
• addressees
• adoptees
• allottees
• amputees
• antifreeze
• appellees
• appointees
• arrestees

Kids Definition

Alzheimer's disease

noun

Alz·​hei·​mer's disease ˈälts-ˌhī-mərz  ˈalts- 

: a brain disease of later life that is characterized by changes in brain tissue with gradual loss of memory and mental abilities

called also Alzheimer's

Medical Definition

Alzheimer's disease

noun

Alz·​hei·​mer's disease ˈälts-ˌhī-mərz-  ˈȯlts-  ˈalts-  ˈalz- 

variants also Alzheimer disease

-mər 

or Alzheimer's

: a degenerative brain disease of unknown cause that is the most common form of dementia, that usually starts in late middle age or in old age, that results in progressive memory loss, impaired thinking, disorientation, and changes in personality and mood, that leads in advanced cases to a profound decline in cognitive and physical functioning, and that is marked histologically by the degeneration of brain neurons especially in the cerebral cortex and by the presence of neurofibrillary tangles and plaques containing beta-amyloid

Behavioral problems, such as mood swings and agitation, may also be a part of the progression of Alzheimer's disease.

—Allan Perel, The Staten Island (New York) Advance

Alzheimer disease (AD) is the most common cause of dementia, affecting more than 15 million individuals worldwide.

—Niklas Mattsson et al., The Journal of the American Medical Association

… researchers in California have created mice carrying the gene for beta-amyloid protein, the principal component of the plaques riddling the brains of people with Alzheimer's.

—Charlene Crabb, U.S. News & World Report

—abbreviation AD