The course of Alzheimer's disease is not the same in every person, but symptoms seem to develop over the same general stages. In most people with Alzheimer's, symptoms first appear in their mid-60s.
Scientists know that Alzheimer’s progresses on a spectrum with three stages—an early, preclinical stage with no symptoms; a middle stage of mild cognitive impairment (MCI); and a final stage of Alzheimer’s dementia. At this time, doctors cannot predict with any certainty which people with MCI will or will not develop Alzheimer’s.
The first symptoms of Alzheimer’s vary from person to person. Memory problems are typically one of the first signs of cognitive impairment related to Alzheimer's disease. For many, decline in non-memory aspects of cognition, such as word-finding, vision/spatial issues, and impaired reasoning or judgment, may signal the very early stages of Alzheimer’s disease. Read more about other early signs of Alzheimer's »
As the disease progresses, people experience greater memory loss and other cognitive difficulties. Problems can include:
Alzheimer's disease is often diagnosed at this stage.
In this stage, damage occurs in areas of the brain that control language, reasoning, sensory processing, and conscious thought. Symptoms may include:
People with severe Alzheimer's cannot communicate and are completely dependent on others for their care. Near the end, the person may be in bed most or all of the time as the body shuts down. Their symptoms often include:
For more detailed information on signs and symptoms of Alzheimer's disease, read the section in Alzheimer's Disease: Unraveling the Mystery, "The Changing Brain in AD."
A growing body of research has shown that Alzheimer’s may cause changes in the brain a decade or more before symptoms appear and that symptoms do not always directly relate to abnormal changes in the brain caused by Alzheimer’s. To reflect these findings, the National Institute on Aging and the Alzheimer’s Association collaborated to develop updated diagnostic guidelines for Alzheimer’s disease, released in April, 2011. Read more about the updated diagnostic guidelines »