Several attempts have been made to categorize the symptoms of Alzheimer’s disease by stages. While having a staging system does provide a quick way to measure the progression of Alzheimer’s disease, systems that stage Alzheimer’s symptoms are only guidelines. For instance, memory loss may progress at a slower or faster rate, and some may not suffer from severe personality changes.

Nevertheless, staging Alzheimer’s symptoms gives some indication of how the disease is progressing in a patient. Alzheimer’s symptoms can be ranked as mild, moderate, or severe. Some medical professionals will use a simple three-tier system for Alzheimer stages: early, mid, and late-stage. The most detailed Alzheimer stages system divides Alzheimer’s symptoms into seven stages:

• Stage 1: The person has no apparent cognitive impairment or memory loss and has normal decision making ability.
• Stage 2: The person experiences slight cognitive decline and begins to forget small details, such as the location of car keys, glasses or a book.
• Stage 3: Cognitive decline may start to become noticeable. Other people notice memory loss. At this stage, Alzheimer’s symptoms may be clinically identifiable.
• Stage 4: The person begins to forget recent events and personal details. Decision making ability begins to become impaired. He or she may seem socially withdrawn.
• Stage 5: Memory loss continues. Decision making ability worsens. The person requires assistance with some daily tasks.
• Stage 6: Decision making ability is severely impaired. The person requires constant care. Personality changes may occur.
• Stage 7: The person cannot perform any decision making, does not respond to stimuli, and cannot control movement. The person is often mute.

Regardless of Alzheimer stages, some patients may have moments of clarity in which they recognize faces, can put names to those faces, and have vivid memory recall. Oftentimes these moments of clarity are triggered by familiar smells, sounds, and voices.