Alzheimer’s Disease and Other Dementias

Being a caregiver for someone with Alzheimer’s Disease or other dementias is challenging! Below you will find high-level information about the most common dementias; be sure to check out our FAQ section for answers to common questions

Topic Quick Links – Click on a topic below to go to that area of the page.


Dementia is not a specific illness but a syndrome or group of symptoms which causes memory problems affecting everyday life. Dementia has a gradual onset and get progressively worse. The burden of Alzheimer’s disease and related dementias in 2014 was 5 million people, which is 1.6 percent of the U.S. population in 2014—319 million people. This burden is projected to grow to 13.9 million, nearly 3.3 percent of the population in 2060–417 million people.

It is estimated that 5% of people over age 65 and 20% of those over 85 have some form of dementia. Alzheimer’s disease accounts for 60% of all cases of dementia with 15-20% caused by strokes (cerebrovascular dementia) and 15-20% resulting from other neuro-psychological disorders, i.e. Parkinson’s disease and Huntington’s disease.

Alzheimer’s Disease

Alzheimer’s disease is an illness of the brain that causes nerve cells in the brain to die. It results in disrupted memory, thinking and functioning. While everyone who has Alzheimer’s disease has dementia, not everyone who has dementia has Alzheimer’s disease. The only definite diagnosis for Alzheimer’s disease is finding plaques and tangles in the brain during autopsy. There is a somewhat greater risk for people with a family history of the disease. Race or ethnicity does not seem to be a factor. To learn more visit The Alzheimer’s Association’s website.

Diagnosis of dementia or Alzheimer’s is based on a range of tests:

  • A complete medical history includes information about the person’s general health, past medical problems, and any difficulties the person has carrying out daily activities.
  • Medical tests – such as tests of blood, urine, or spinal fluid – help the doctor find other possible diseases causing the symptoms.
  • Neuropsychological tests measure memory, problem solving, attention, counting, and language.
  • Brain scans allow the doctor to look at a picture of the brain to see if anything does not look normal.

Here are the ten warning signs of Alzheimer’s disease:

  1. Memory loss 
  2. Difficulty performing familiar tasks
  3. Problems with language
  4. Disorientation to  time and place
  5. Poor or decreased judgment
  6. Problems with abstract thinking
  7. Misplacing things
  8. Changes in mood or behavior
  9. Changes in personality
  10. Loss of initiative

There are three main stages of Alzheimer’s disease:

Mild – 

  • Often looks and acts normal
  • Short-term memory fades making it difficult to learn new things
  • Speech becomes slightly impaired
  • Hygiene can be neglected and judgment hindered
  • Minor personality changes
  • Emotional response unpredictable and exaggerated
  • “Sundown Syndrome” of late afternoon or early evening may include agitation, confusion, or restlessness can occur at this stage or in the next (moderate) stage

Moderate –

  • Memory impairment is obvious
  • Short term memory vanishes and stories and actions are likely to be repeated over and over again
  • Individual needs supervision as complex tasks become overwhelming and decision-making is impaired
  • Sleep cycles are disrupted
  • Poor coordination, agitation, wandering and pacing may emerge Contact local Alzheimer’s Associations about their Safe Return Program
  • Behavior problems are more frequent with exaggerated moods, hostility and aggression

Severe –

  • Person needs help in basic activities of daily living, such as bathing, eating and toileting
  • Fragments of memory remain
  • Troublesome behaviors are less prevalent
  • Individuals suffer acute confusion, hallucination, delusions, paranoia, physical rigidity and/or seizures

Multi-Infarct Dementia

Multi-infarct dementia results from repeated strokes that destroy small areas of the brain. It can lead to dementia, Alzheimer’s disease, other strokes, migraine-like headaches and disturbances of coordination and speech. Symptoms depend on the area of the brain that is affected. Individuals may improve for short periods of time but then decline again.

With multi-infarct dementia, damage is noticeable as a series of small steps:

  • confusion
  • problems with recent memory
  • wandering or getting lost in familiar places
  • loss of bladder or bowel control (incontinence)
  • emotional problems such as laughing or crying inappropriately
  • difficulty following instructions, and problems handling money

Multi-infarct dementia generally begins between the ages of 60 and 75 and affects men more often than women. Early treatment and blood pressure management may prevent further progression.

Written by:  Zanda Hilger, M. Ed., LPC, Family Caregiver Education, Area Agency on Aging, Revised 2021