What is Alzheimer’s?

Alzheimer’s disease (AD) is a neurological (or brain) condition that slowly and progressively leads to loss of memory, judgment, attention, and reasoning.1  AD has stages and is considered a neurodegenerative disease, characterized by damage to the brain and loss in ability of nerve cells (neurons) to send messages between different parts of the brain as well as from the brain to muscles and other organs in the body.1-3 It is not the same as becoming forgetful over time—AD is not a normal part of the aging process.4

AD is the most common type of dementia, especially in people over the age of 65.4 While AD usually affects people over 65, it can occur in younger people in a small percentage of cases (early Alzheimer’s).1,4 Survival for those living with Alzheimer’s can average 4-8 years after diagnosis, but as many as 20 years depending on individual factors.4

How the Brain is Affected in Alzheimer's Disease

Scientists are still learning the precise mechanism of AD and its stages, but they know that damage to brain tissue is involved.3 Even before symptoms start, the brain can start to show changes in the brain, such as an abnormal buildup of proteins like amyloid plaques (protein clumps) around blood vessels and nerve cells, and tau neurofibrillary tangles (bundles of fibers) within the nerve cells themselves.1,3,4 As AD progresses, the nerve cells lose the ability to communicate with each other (and the rest of the body) and die.3,4 Losing nerve cells causes the brain to shrink and leads to the symptoms associated with AD, such as memory loss, personality changes and trouble performing daily activites.4

How Can I Reduce My Risk for Alzheimer's Disease?

Despite all of the scientific advances in this field, scientists are still working to understand what causes AD.3 The causes are likely a combination of genetic, environmental, and lifestyle factors, and can vary from person to person.3 Age is the greatest known risk factor for AD as well as other dementias; however, increasing age is not a direct cause of AD.7 While risk factors such as age, family history and heredity cannot be modified, research is beginning to reveal clues about other risk factors that can be modified via changes in lifestyle and via effective management of other health conditions7

Get treatment for conditions that affect your heart and blood vessels, like diabetes, heart disease, stroke, high blood pressure and high cholesterol

Avoid head injuries – wear a seatbelt in the car and a helmet with sports

Eat a healthy diet

Stay socially active

Quit smoking

Avoid excess alcohol

Exercise your body and mind

What are the symptoms of Alzheimer's Disease?

The symptoms of AD typically get worse as the condition progresses due to the loss of functioning brain tissue.3,4 One of the early symptoms of AD, and one of the most common symptoms is remembering newly learned information.4 As the disease spreads throughout the brain, people with severe AD have trouble communicating and are often completely dependent on their caregivers.3 Closer to the end of life, the body shuts down and the person may have to stay in bed most or all of the time.3 AD is among the top ten leading causes of death among American adults.8

Here is a summary of the symptoms that can be experienced in the varying stages of Alzheimer’s Disease.


  1. Kumar A, Sidhu J, Goyal A, et al. Alzheimer Disease. StatPearls. 2022. https://www.ncbi.nlm.nih.gov/books/NBK499922/
  2. National Institute of Environmental Health Sciences. Neurodegenerative diseases. Last reviewed June 9, 2022. https://www.niehs.nih.gov/research/supported/health/neurodegenerative/index.cfm
  3. National Institute on Aging (NIA). Alzheimer’s Disease Fact Sheet. https://www.nia.nih.gov/health/alzheimers-disease-fact-sheet
  4. Alzheimer’s Association®. What is Alzheimer’s disease? https://www.alz.org/alzheimers-dementia/what-is-alzheimers
  5. Breijyeh Z, Karaman R. Comprehensive Review on Alzheimer’s Disease: Causes and Treatment. Molecules. 2020;25(24):5789.
  6. Cedar City News Archives. How your ears can cause brain shrinkage, dementia. 10/31/2015. https://archives.cedarcityutah.com/news/archive/2015/10/31/hw-how-your-ears-can-cause-brain-shrinkage-dementia#.Y2H4zC2B29Q
  7. Alzheimer’s Association®. Causes and risk factors for Alzheimer’s disease. https://www.alz.org/alzheimers-dementia/what-is-alzheimers/causes-and-risk-factors
  8. Centers for Disease Control and Prevention. (CDC). Leading Causes of Death. https://www.cdc.gov/nchs/fastats/leading-causes-of-death.htm
  9. Alzheimer’s Association®. Stages of Alzheimer’s. https://www.alz.org/alzheimers-dementia/stages
  10. 2023 Alzheimer’s disease facts and figures. Alzheimers Dement. 2023;19(4):1598-1695. doi:10.1002/alz.13016
  11. National Institute on Aging (NIA). What are the Signs of Alzheimer’s Disease. https:www.nia.nih.gov/health/what-are-signs-alzheimers-disease

All URLs accessed February 14, 2024.

Scientific Council

Marc Agronin, MD

Chief Medical Officer
Frank C. and Lynn Scaduto MIND Institute and Behavioral Health
Miami Jewish Health
Miami, FL

Liana G. Apostolova, MD, MSc, FAAN

Indiana University Distinguished Professor
Barbara and Peer Baekgaard Professor in Alzheimer's Disease Research
Professor in Neurology, Radiology, Medical and Molecular Genetics
Indiana University School of Medicine
Department of Neurology
Indianapolis, IN

Alireza Atri, MD, PhD

Director, Banner Sun Health Research Institute
Banner Health
Sun City, AZ
Lecturer on Neurology, Center for Brain/Mind Medicine
Brigham and Women’s Hospital and Harvard Medical School
Boston, MA

Ariel F. Cole, MD, FAAFP

Program Director, AdventHealth Geriatric Fellowship
Winter Park, FL

Brad Dickerson, MD, MMSc, FAAN

Director, Massachusetts General Hospital
Frontotemporal Disorders Unit
Professor of Neurology, Harvard Medical School
Boston, MA

Richard M. Dupee, MD, MACP, AGSF

Clinical Professor of Medicine
Tufts University School of Medicine
Clinical professor, Department of Public Health and Community Medicine, Tufts University
Chief, Geriatrics Service, Tufts Medical Center
Senior Physician, Pratt Diagnostic Center
Dean ex officio, Office of International Affairs, Tufts University School of Medicine
Boston, MA

James E. Galvin, MD, MPH

Professor of Neurology
University of Miami Miller School of Medicine
Miami, FL

David S. Geldmacher, MD

Professor and Director
Division of Memory Disorders and Behavioral Neurology
Department of Neurology
Heersink School of Medicine
University of Alabama at Birmingham
Birmingham, AL

George T. Grossberg, MD

Henry & Amelia Nasrallah Endowed Professor
Department of Psychiatry and Behavioral Neuroscience
Saint Louis University School of Medicine
St. Louis, MO

Scott A. Kaiser, MD

Director of Geriatric Cognitive Health
Pacific Neuroscience Institute
Santa Monica, CA

Diana R. Kerwin, MD, CPI

President, Kerwin Medical Center
Chief, Geriatric Medicine, Texas Health Presbyterian Hospital
Dallas, TX

Scott McGinnis, MD

Assistant Professor of Neurology, Harvard Medical School
Center for Alzheimer Research and Treatment
Brigham and Women's Hospital
Frontotemporal Disorders Unit
Massachusetts General Hospital
Boston, MA

Manisha Parulekar, MD, FACP, AGSF, CMD

Director, Division of Geriatrics
Co-director, Center for Memory Loss and Brain Health
Hackensack University Medical Center
Hackensack, NJ

Giulio M. Pasinetti, MD, PhD

The Saunders Family Chair and Professor of Neurology
Director of the Center for Molecular Integrative Neuroresilience,
Professor of Psychiatry and Neuroscience
Professor of Geriatrics and Adult Development
Department of Neurology and Friedman Brain Institute
Icahn School of Medicine at Mount Sinai
New York, NY

William D. Rhoades, DO, FACP

Chief Medical Officer
Advocate Good Samaritan Hospital
Downers Grove, IL

Marwan Noel Sabbagh, MD, FAAN, FANA

Vice Chairman for Research and Professor
Department of Neurology
Barrow Neurological Institute
Phoenix, AZ

Paul E. Schulz, MD

Rick McCord Professor in Neurology
Umphrey Family Professor of Neurodegenerative Diseases
Director, Neurocognitive Disorders Center
Director, Neurocognitive Disorders Fellowship
McGovern Medical School at UTHealth Houston
Houston, TX

Neil Skolnik, MD

Professor of Family and Community Medicine
Sidney Kimmel Medical College
Thomas Jefferson University
Philadelphia, PA

R. Scott Turner, PhD, MD

Professor of Neurology
Director of the Memory Disorders Program
Georgetown University
Washington, DC

Chuck Vega, MD, FAAFP

Health Sciences Clinical Professor
UC Irvine Department of Family Medicine
Director, UCI Program in Medical Education for the Latino Community
Irvine, CA

Geoffrey C. Wall, PharmD, FCCP, BCPS

John R. Ellis Distinguished Chair of Pharmacy Practice
Professor of Clinical Sciences
Director, Drake Drug Information Center
Drake University College of Pharmacy and Health Sciences
Internal Medicine Clinical Pharmacist
Iowa Methodist Medical Center
Des Moines, IA

David A. Wolk, MD, FAAN

Professor of Neurology
Director, Penn Alzheimer’s Disease Research Center
University of Pennsylvania
Philadelphia, PA