Alzheimer’s disease is a progressive, degenerative disease that affects thinking and memory function. In order to classify the progression of the disease, researchers have outlined some distinct stages of Alzheimer’s disease. These stages are a useful tool for doctors, as they offer some indication as to how far a particular patient’s condition has progressed.

Symptoms fall into one of three distinctive Alzheimer’s disease stages: mild, moderate or severe. These stages correspond to early, mid and late stages of Alzheimer’s. Because these Alzheimer’s disease stages are rather broad, some medical professionals prefer to use the Global Deterioration Scale (GDS) or the Reisberg Scale.

Seven Stages of Alzheimer’s Disease

The Global Deterioration Scale offers a more detailed categorization of disease progression, dividing symptoms into seven different stages of Alzheimer’s disease:

  • Stage 1: No cognitive impairment. The individual does not exhibit any cognitive impairment or loss of memory.
  • Stage 2: Very mild cognitive decline. The individual experiences mild memory loss (i.e. forgetting people’s names or the location of personal belongings).
  • Stage 3: Mild cognitive decline. Memory loss often becomes noticeable at this stage. Other Alzheimer’s symptoms, such as disorientation and communication challenges, may also be clinically identifiable.
  • Stage 4: Moderate cognitive decline. Memory loss extends to recent events and personal details. The individual begins to lose his ability to perform complex tasks (i.e. mathematical problems). He may also become socially withdrawn.
  • Stage 5: Moderately severe cognitive decline. The individual now demonstrates significant gaps in memory and is often confused. She may exhibit other behavioral changes as well. Decision-making ability is further impaired. She may require assistance with some daily tasks.
  • Stage 6: Severe cognitive decline. Memory function and decision-making ability are severely impaired. Constant care is required.
  • Stage 7: Very severe cognitive decline. The individual ceases to communicate or respond to stimuli. He cannot move without assistance.

A Final Word: Alzheimer’s Disease Stages

The stages of Alzheimer’s merely serve as a guideline for medical professionals. Alzheimer’s disease affects people differently, and not every individual will go through every stage of the disease exactly as outlined above. For example, some people may experience rapid loss of memory function, while others experience a much slower deterioration. Some individuals never exhibit personality or behavioral changes.

At any one of these stages of Alzheimer’s, an individual may have moments of vivid memory recall, remembering, for example, the face of a loved one. Familiar sights, sounds and smells can trigger these moments of clarity.


Alzheimer’s Association. (n.d.) Stages of Alzheimer’s. Retrieved June 11, 2010, from

Alzheimer Society of Canada. (n.d.) What is Alzheimer’s disease? Retrieved April 23, 2010, from

Fisher Center for Alzheimer’s Research Foundation. (n.d.) Clinical stages of Alzheimer’s disease. Retrieved June 11, 2010, from

Mayo Clinic. (2008). Alzheimer’s stages: How the disease progresses. Retrieved June 11, 2010, from:

 Posted on : June 14, 2014