by EBSCO Medical Review Board

Alzheimer disease is a brain disorder. People lose the ability to think, reason, and remember. Symptoms can change from day to day. Over time the disease gets worse. Alzheimer dementia is when a person can no longer care for him or herself.

Areas of the Brain Affected by Alzheimer Disease
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Brain cells stop working and begin to die. Why this happens is not clear. It could be a mix of:

  • Genes
  • Environment
  • Overall health
  • People with Alzheimer disease have more things called tangles and plaques in their brains. These may block how the cells talk to each other. They are:

    • Neurofibrillary tangles—pieces of a protein called tau fibers are twisted in the cells
    • Neuritic plaques—a protein called beta amyloid builds up between nerve cells

    These changes often start where the brain stores memory. This damage may begin many years before a person has symptoms.

    What are the risk factors for Alzheimer disease?What are the symptoms of Alzheimer disease?How is Alzheimer disease diagnosed?What are the treatments for Alzheimer disease?Are there screening tests for Alzheimer disease?How can I reduce my risk of Alzheimer disease?What questions should I ask my doctor?Where can I get more information about Alzheimer disease?


    Alzheimer dementia. EBSCO DynaMed website. Available at: Accessed April 6, 2022.

    Alzheimer's disease medications fact sheet. National Institute on Aging website. Available at: Accessed April 6, 2022.

    Atri, A. The Alzheimer's Disease Clinical Spectrum: Diagnosis and Management. Med Clin North Am. 2019; 103(2): 263-293.

    What is Alzheimer's? Alzheimer’s Association website. Available at: Accessed April 6, 2022.

    Revision Information

    • Reviewer: EBSCO Medical Review Board Rimas Lukas, MD
    • Review Date: 03/2022
    • Update Date: 04/06/2022