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What We Know Today About Alzheimer's Disease and Dementia

About Alzheimer's Inside the Brain Causes Treatments

About Alzheimer’s and dementia

Alzheimer's disease is a progressive brain disorder that damages and eventually destroys brain cells, leading to memory loss and changes in thinking and other brain functions. It usually develops slowly and gradually gets worse as brain function declines and brain cells eventually wither and die. Ultimately, Alzheimer's is fatal, and currently, there is no cure.

But neuroscience research efforts are under way to develop effective treatments and ways to prevent the disease. Researchers are also working to develop better ways to care for affected people and better ways to support their families, friends and caregivers. The Alzheimer's Association is moving these research efforts forward by funding scientists who are searching for more answers and new treatments, collaborating with stakeholders, fostering worldwide partnerships among scientists, and raising the visibility of Alzheimer's as a global health challenge.

Alzheimer's disease is the most common type of dementia, a general term used to describe various diseases and conditions that damage brain cells. Alzheimer's disease accounts for 60 to 80 percent of dementia cases. Other types include vascular dementia, dementia with Lewy bodies and frontotemporal dementia. In some cases, a person may have more than one type and are said to have mixed dementia.

Hallmark changes of Alzheimer's

Brain tour
Learn more about brain changes. The image above shows amyloid plaques and tau protein tangles in blue.

Scientists have identified several hallmark Alzheimer's brain abnormalities, including:

  • Plaques, microscopic clumps of a protein fragment called beta-amyloid
  • Tangles, twisted microscopic strands of the protein tau (rhymes with "wow")
  • Loss of connections among brain cells responsible for memory, learning and communication. These connections, or synapses, transmit information from cell to cell.
  • Inflammation, triggered by the body's immune system
  • Eventual death of brain cells and severe tissue shrinkage

Take our interactive Brain Tour to see Alzheimer's changes in the brain.

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Growing awareness and concern

Key events during the past 100 years spurred public awareness of Alzheimer's disease and ignited a massive research effort to learn more.

See more milestones

Symptoms of Alzheimer's

Patterns of plaques and tangles

The most common early symptom is difficulty remembering newly learned information because Alzheimer's changes typically begin in the part of the brain that affects learning. As Alzheimer's advances through the brain it leads to increasingly severe symptoms, including disorientation; mood and behavior changes; deepening confusion about events, time and place; unfounded suspicions about family, friends and professional caregivers; serious memory loss and behavior changes; and difficulty speaking, swallowing and walking.

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Related information


Alzheimer's Association International Conference | July 16-20, 2017, London, England

Abstract Submissions Now Open

The Scientific Program Committee is now accepting submissions for poster
presentations, oral presentations and featured research sessions.