A person showing another person with Alzheimer's Disease a photograph

Alzheimer’s Disease

Alzheimer's disease is a progressive neurological disease that ultimately results in the brain's inability to function correctly. 

Symptoms of Alzheimer's include problems with memory, communication, comprehension, and judgment. Changes in personality may also occur. As the disease progresses, the ability to function mentally, socially, and physically continues to decline.

Alzheimer's disease is the most common type of dementia and is typically seen in older adults. There is no cure, but symptoms can be managed through the use of behavioral strategies and medication.

Frequently Asked Questions

  • What causes Alzheimer's disease?

    The exact cause of Alzheimer's disease hasn't been identified. The current thinking is that it develops due to a combination of genetic, lifestyle, and environmental risk factors.1

    The brains of people with Alzheimer’s often show a build-up of proteins, known as plaques and tangles. Over time, these proteins can lead brain tissue to atrophy (shrink).

  • What is the difference between dementia and Alzheimer's?

    Dementia is a general term that covers many types of cognitive impairment. Alzheimer’s disease is the most common form of dementia; other types include vascular dementia and dementia with Lewy bodies. Symptoms vary among the types, but generally include memory loss, poor judgment, communication difficulties, and personality changes.

  • Is Alzheimer's genetic?

    Alzheimer’s disease is considered a complex “multifactorial” disorder, meaning it is caused by environmental circumstances combined with genetic factors. Recent research has identified several gene mutations that are linked with both late-onset and early-onset forms of the disease.

  • How is Alzheimer’s diagnosed?

    A definitive diagnosis of Alzheimer’s cannot be made until a brain autopsy after death. However, there are numerous tests that can be done at home or by a doctor that measure cognitive impairment and other factors that suggest Alzheimer’s, leading to a probable diagnosis.

  • Can you prevent Alzheimer's?

    There is no known way to prevent Alzheimer’s, since its causes are thought to be due to a variety of factors, including genetic and environmental factors. However, remaining intellectually and socially engaged throughout your life may contribute to brain health. Leading a healthy lifestyle by exercising and maintaining a healthy weight is good for overall health, including brain health.

  • Is there a cure for Alzheimer's disease?

    There is no cure yet for Alzheimer's disease, though there are strategies and medications that can keep symptoms under control. Meanwhile, research continues to reveal more about how Alzheimer's affects the brain, which may ultimately lead to the development of a cure.

  • Is Alzheimer's a disease?

    Alzheimer’s is a complex disease with many manifestations. Symptoms increase in severity as it progresses through three main stages—early-, mid-, and late-stage disease. The cause of death in someone with Alzheimer’s is often related to a physical complication, such as aspiration pneumonia due to a decline in the ability to swallow.

  • What are the early signs of Alzheimer’s?

    The ten most common signs of Alzheimer’s include: memory changes; withdrawal from usual activities; disorientation to time and place; visual-spatial difficulties; decrease in written or verbal communication ability; challenges in problem-solving and planning; personality and mood changes; misplacing items frequently; decline in judgment; and difficulty performing familiar tasks. These signs often become more severe as the disease progresses.

Key Terms

How Alzheimer's Changes the Brain

Someone pricking their finger to test blood sugar levels
Why Alzheimer's Disease Is Called Type 3 Diabetes
Worried man sitting at a laptop
How to Know If You Have Early Onset Alzheimer's
Nurse helping woman walk with walker
What to Expect in the Middle Stages of Alzheimer's Disease
Illustrations of a human brain
How Gray Matter Is Affected by Dementia
a doctor studying brain scans
Get Info on the Significance of White Matter in the Brain
mother and daughter hugging
Is Alzheimer's Disease Contagious?
Dementia Support Group
The 7 Best Dementia Support Groups of 2021
What Does ApoE 4 Have to Do With Alzheimer’s Disease?
Alois Alzheimer Seated at Left with Other Psychiatrists
Who Was Alois Alzheimer and How Was Alzheimer's Disease Discovered?
Alzheimer's Disease Support Group
The 6 Best Alzheimer's Disease Support Groups of 2021
SPECT Scanner.
What to Expect When Undergoing a SPECT Scan
Patient talking to doctor
Hereditary Risk Factors of Alzheimer’s Disease
Woman blowing out candles on birthday cake
How Important Is Age as an Alzheimer's Risk Factor?
Doctor viewing patient's brain scan on digital tablet in laboratory
The Amyloid Cascade Hypothesis of Alzheimer's Disease
Anesthesia in Surgery
Does Anesthesia Increase Your Risk of Alzheimer's?
diverse people
How Your Race Impacts Your Risk of Dementia
Woman talking with senior about her memory
What Is the Allen Cognitive Level Screen?
Older woman taking to healthcare provider
Montreal Cognitive Assessment (MoCA) Test for Dementia
Does that mean what I think it does?
Use and Scoring of the ADAS-Cog Test
Alzheimer's and Other Dementia Screenings
Screening Tests Used for Alzheimer's and Other Dementias
Woman with Dementia and Depression
All about the Cornell Scale for Depression in Dementia
Doctor and patient chat about the verbal fluency test
How the Verbal Fluency Test Is a 60-Second Screening for Dementia
Physician Talking about the AD8 Alzheimer's Screening Results
AD8 Dementia Screening Interview for Caregivers
Sense of Smell Is Correlated with Cognition
Does a Poor Sense of Smell Predict Alzheimer's Disease?
Daughter Worried about Her Mother's Memory
Are You Worried That Your Loved One Has Alzheimer's or Dementia?
Alzheimer's Patient
What Memory and Thinking Tests Do Doctors Use to Evaluate Dementia?
Confused Facial Expression on senior woman
Can You Tell If Someone Has Dementia by Watching Them?
Hands of older woman writing in journal
Can a 7-Minute Screening Test Determine If You Have Dementia?
doctors examining MRI results
How MRI is Used to Help Doctors Detect Alzheimer's Disease
The Clock Drawing Test Can Screen for Dementia
Scoring and Interpreting the Clock Drawing Test for Dementia
Milk spilling from baby bottle
Can the Proverb Interpretation Test Screen for Dementia?
Doctor Administering the Boston Naming Test
What Is the Boston Naming Test? How Is It Used to Screen for Dementia?
Older woman talking to physician
Can the Mini-Mental State Exam (MMSE) Diagnose Alzheimer's?
Taking the SAGE Dementia Test at Home
How Accurate Is the Online SAGE Dementia Test?
Nurse writing medical report for senior patient in care home
How Accurate Is a BIMS Score in Identifying Dementia?
Doctor providing digit symbol substitution test results
What Is the Digit Symbol Substitution Test?
A senior black man is sitting in his doctor's office and listening as the doctor shows him something on a digital tablet.
How Does the Digit Span Test Screen for Delirium and Dementia?
High angle view of a senior woman doing Alzheimer's disease cognitive functions self assessment test at home
How the GPCOG Screening Tool Is Used to Screen for Dementia
Memory Impairment Screen Being Administered
A 4-Minute Test: The Memory Impairment Screen (MIS)
The SLUMS Test Can Help Screen for Early Alzheimer's
How Well Does the SLUMS Test Screen for Dementia?
Doctor talking about the Trail Making Test
The Trail Making Test and Its Use as a Screening Tool for Dementia
Doctor talking with patient about her Mini-Cog test results
How the Mini-Cog Is Used to Test for Alzheimer's and Dementia
Doctor Explaining the Results of the Stroop Test
How the Simple Stroop Test Detects Signs of Early Alzheiemr's
Benefits of Early Detection in Alzheimer's
12 Benefits of Early Detection in Alzheimer's Disease
a group of seniors exercising
How Physical Therapy Can Be Beneficial for Alzheimer's Disease
How a Urinalysis Can Detect a UTI in Dementia
How Do Urinary Tract Infections (UTIs) Affect People With Dementia?
Man and woman walking down hallway of care facility
Do People With Dementia Die Faster in Nursing Homes or at Home?
A woman writing on sticky notes
Explore These 7 Easy Tips to Improve Your Memory and Recall
College student using elaborative rehearsal
Elaborative Rehearsal: A Better Way to Memorize
Using Keyword Mnemonics to Improve Ability to Memorize and Recall
Older woman and her daughter
10 Things People With Dementia Wish You Knew
An older man reading his book on a dock
Effects of Dementia on Instrumental Activities of Daily Living
Senior men laughing
How to Improve Quality of Life for Someone Who Has Alzheimer's
Senior mother and daughter hugging
Life Expectancy of Patients With Alzheimer's Disease and Dementia
Incontinence Can Be a Challenge in Dementia
Your Guide to Coping With Urinary and Fecal Incontinence in Dementia
Festively wrapped Christmas gift, close-up
Discover These 7 Tips for Celebrating the Holidays in a Nursing Home
Gardening in Dementia Can Create Joy
Planning a Garden for Persons With Alzheimer's and Other Dementias
A young person cares for her older loved one with Alzheimer's disease
Coping With Advanced Alzheimer's Disease: Advice for Caregivers
Gifts for people with dementia
The 10 Best Gifts for People with Dementia of 2021
Grandfather and son in garden
Truths to Learn From People Living With Dementia
Page Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.