Alzheimer's Disease

Alzheimer's disease (AD) is a progressive, neurodegenerative disease characterized by memory loss, language deterioration, impaired ability to mentally manipulate visual information, poor judgment, confusion, restlessness, and mood swings.

AD usually begins after age 65, but its onset may occur as early as age 40, appearing first as memory decline and, over several years, destroying cognition, personality, and ability to function. Confusion and restlessness may also occur. The type, severity, sequence, and progression of mental changes vary widely. However, there are some early-onset forms of the disease, usually linked to a specific gene defect, which may appear as early as age 30.

The early symptoms of AD, which include forgetfulness and loss of concentration, can be missed easily because they resemble signs of natural aging. Similar symptoms can also result from fatigue, grief, depression, illness, vision or hearing loss, the use of alcohol or certain medications, or simply an overwhelming burden of details to remember.

Alzheimer's Disease. Last reviewed 12/31/1969
  • National Institute of Mental Health
  • National Institute of Aging (2006). Alzheimers Disease Fact Sheet
  • National Institute of Aging (2007). Understanding Stages and Symptoms of Alzheimer's Disease
  • National Institute of Neurological Disorders and Stroke
  • National Institutes of Health - National Library of Medicine