What are the stages of Alzheimer's disease?

Alzheimer's disease is the most common cause of dementia in individuals over 65 years of age. Dementia means that there is a loss of memory, thinking, problem-solving, ability to plan and organize, language problems, lack of judgment, and personality changes – all of which interfere with a person’s ability to function.

The different stages of Alzheimer’s disease are summaries of the changes in abilities typically seen in persons with the disease. The symptoms of Alzheimer’s disease worsen over time. Each person with Alzheimer’s disease will progress through the stages of Alzheimer’s disease at different speeds. Not all changes will occur in each person and the decline that occurs may overlap stages.

Prodromal or preclinical stage

Changes in the brain known to be associated with Alzheimer’s disease are happening during this stage but the patient is not showing signs of disease. This stage can last for years or even decades. People in this stage are usually not diagnosed with Alzheimer’s disease yet because they are functioning at a high level. However, there are now brain imaging tests that can detect deposits of a protein in the brain called amyloid. This protein interferes with the brain’s communication system.

Alzheimer’s disease also runs in families (genetic link). Genetic tests can determine if a person with a family history is at a higher risk for the development of Alzheimer’s disease.

Mild stage

In this stage, symptoms begin to be noticeable. People with mild Alzheimer’s disease:

  • Forget newly learned information, especially recent events, places and names
  • Have difficulty finding the right words to express thoughts
  • Have confusion about time and place
  • Repeat the same questions over and over
  • Have difficulty making plans/organizing
  • Have difficulty problem-solving
  • Take longer to complete normal daily tasks
  • Have difficulty completing complicated tasks such as managing money and paying bills
  • Lack sound reasoning/judgment
  • Lose or misplace objects
  • Experience changes in personality

Most people in the mild stage have no problem recognizing familiar faces and can usually travel to familiar places. Many persons with mild Alzheimer's disease may still be driving.

Moderate stage

People in the moderate stage of Alzheimer's require assistance. People in this stage:

  • Have increased memory loss and confusion, often forgetting events or details about their own life
  • Have growing confusion about day of the week, season and where they are
  • Have poor short-term memory
  • Have some difficulty recognizing friends and family
  • Repeat stories or thoughts or events that are on their minds
  • Have difficulty with simple arithmetic
  • May need help choosing proper attire and may need help putting clothes on in the right order
  • Have difficulty carrying out multi-step tasks
  • May need some help with self-care, such as bathing, grooming, showering and toileting
  • Experience more changes in personality including being agitated, acting out. May show delusional behavior, depression, apathy, or anxiety as the disease progresses.
  • May develop groundless suspicions about family, friends and caregivers
  • May begin to wander from their living area

Moderately severe stage

In this stage of Alzheimer’s disease, the person:

  • Has significant confusion. May not consistently recognize his or her children or spouse, or may confuse them with other family members. May think strangers are family members.
  • Loses skills in dressing, bathing, and then toileting. Urinary incontinence and, later, fecal incontinence occur.
  • Sleep is often disturbed.

Severe stage

In this stage of Alzheimer’s disease, the person:

  • Has almost total memory loss.
  • Need helps with all basic activities of everyday living.
  • Is unaware of his or her surroundings.
  • Begins a decline in ability to sit up, walk or eat without assistance.
  • Loses weight.
  • May have forgotten how to move his or her bowels, or may be incontinent prior to reaching the toilet.

Very severe stage

In this late stage of Alzheimer’s disease, the person:

  • Loses the ability to communicate. Speech becomes limited to a few words or phrases.
  • Forgets how to swallow. This can cause food and drink to enter the lungs and cause an infection.
  • Loses ability to control bladder and bowel function.
  • Develops skin infections.

Hospice care may be appropriate at this time for comfort. Common causes of death include pneumonia, malnutrition and dehydration, and other infections. Persons with Alzheimer’s disease live, on average, four to eight years after diagnosis. Some patients can live as long as 20 years after diagnosis. The course of the disease varies from person to person.

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy