Stages of Alzheimer's Disease – Three Stage Model

The three stage model is a rather arbitrary division, but one that is easier to understand. Even people who have adopted the more detailed seven stage model to describe and follow the progression of the disease speak in terms of "early", "middle", and "late" stage Alzheimer's disease.

What follows is by no means a complete list of symptoms and behavioral changes that can be seen in Alzheimer's disease. Furthermore, many of the symptoms are a part of the normal aging process. Don't assume, if you can't find the car keys one morning, that you are in the early stages of Alzheimer's disease.

Alzheimer's Stages

Stage One Alzheimer's – Mild Alzheimer's Disease

Mild Alzheimer's disease is characterized by some memory loss, especially memory of more recent events. A person in the early stages of Alzheimer's will likely be able to carry out the daily activities of living, but may start forgetting familiar words and names when speaking. Judgment and attention span will become impaired.

Toward the end of the first stage she may get lost, especially in places that are not very familiar. Finding the right words becomes more difficult and she may begin to avoid social situations. Finally, family members and friends may begin to recognize that there is a problem. The ability to initiate, stay with, and complete a task begins to suffer.

It is very likely that the person in the early stages of Alzheimer's disease will recognize that something is happening, that her memory and judgment is being affected. She will often compensate by writing notes to remind herself what she needs to do and when.

Other behavioral symptoms and resulting outcomes include:

  • Impaired logic and sequencing, as when telling a story or joke
  • Words are used incorrectly or made up
  • Inappropriate and broad mood swings
  • Decreased motivation and attention
  • Dresses inappropriately, may put on a winter coat in the middle of summer
  • Conversation becomes difficult and disjointed, may have trouble finishing a sentence or respond inappropriately to questions
  • Gets lost, even in familiar places
  • Physical abilities, balance, strength, etc., begin to diminish
  • Repeats questions or statements
  • May begin to misplace, lose, or hide things
  • Forgetting becomes more pronounced as the stage advances

Apathy and withdrawal, anxiety, aggression, irritability, and anger are more and more in evidence as the first stage progresses. We feel that this is as much a reaction to the realization that one's mental and physical facilities are declining, just as any of us would react to the news that we have a debilitating disease or condition.


Stage Two Alzheimer's – Moderate Alzheimer's Disease

The symptoms of moderate Alzheimer's disease are in large part an increase in the severity of the symptoms of the first stage. Professional and social functioning continue to deteriorate because of increasing problems with memory, logic, speech, and initiative.

Safety becomes an important issue during this stage. Restlessness is a common symptom of Alzheimer's, and often causes the patient to wander. Impaired memory and confusion then result in her getting lost. Driving, especially alone, is out or the question, for her own safety and the safety of others. Impaired muscle control and weakness can make falling an issue.

One of the most difficult aspects of Alzheimer's for loved ones is the point at which the patient begins to forget the names of, or even fails to recognize, friends and family. We usually see this first in this middle stage of the disease.

Other behavioral symptoms and resulting outcomes include:

  • Sequencing and logic become further impaired
  • Increasing difficulty finding the right words, often make up words
  • Mood swings and personality changes become more pronounced
  • Inappropriate judgment becomes a bigger problem
  • Hygiene neglected, likely because of forgetfulness and inability to initiate the behavior necessary
  • Physical abilities further diminish
  • Sleep disturbances become a problem
  • Psychotic behavior, paranoia, hallucinations, and delusions are not unusual as this stage progresses
  • More pronounced memory loss
  • Inappropriate social behavior
  • Sleep disorders, including disruptions in the sleep/wake cycle and sundowning*
  • May lose the ability to read and write
  • Incontinence
  • Repetitive speech and/or movements

*Sundowning refers to disorientation and confusion caused by, or at least experienced, at the end of the day. The cause of this condition isn't understood, but there are simple behavioral and sensory stimulation therapies that can help.


Stage Three Alzheimer's – Severe Alzheimer's Disease

Severe Alzheimer's disease is characterized by almost total memory loss. The person in this last stage of Alzheimer's usually needs help with all of the basic activities of daily living. She will lose the ability to walk unassisted, and eventually even to sit up by herself. The body eventually forgets how to carry out the normal biological functions necessary sustain life.

Other behavioral symptoms and resulting outcomes include:

  • The ability to communicate is lost almost completely
  • Needs help with all activities of daily living
  • Physical abilities further diminish
  • The brain begins to lose the ability even to control the basic biological functions, like swallowing
  • Complete incontinence
  • Becomes unresponsive to stimuli

Death will generally occur because the body can no longer fight off secondary infections or because the organs begin to break down. Pneumonia is one of the most frequent causes of death in late stage Alzheimer's disease.