Alzheimer's Disease - Overview

Alzheimer's disease (AD) is a condition that causes abnormal changes in the brain mainly affecting memory and other mental abilities. Alzheimer's is a disease, not a normal part of aging. Loss of memory is the usual first symptom. As the disease progresses, the loss of reasoning ability, language, decision-making ability, judgment and other critical skills make navigating day-to-day living impossible without help from others, most often a family member or friend. Sometimes, but not always, difficult changes in personality and behavior occur.

Alzheimer's disease poses real challenges for both the person diagnosed with AD and to those who assume caregiving responsibilities. This does not mean that there will no longer be times of joy, shared laughter and companionship. AD often develops gradually, offering time to adjust to the diagnosis, plan ahead, and spend quality time together.

Nearly 15 million Americans provide unpaid care to a person living with Alzheimer's disease or another dementia (Alzheimer's Association 2011 Facts & Figures). Dr. Alois Alzheimer, a German psychiatrist and neuropathologist is credited with identifying the first published case of "presenile dementia" in 1907, a condition that is now called Alzheimer's disease.



Alzheimer's is the most common form of dementia in older adults. The words "Alzheimer's" and "dementia" are often used interchangeably, but they are not the same. "Dementia" is a term that means a person is no longer able to function on their own because of a lasting impairment of multiple mental abilities affecting memory, attention, and reasoning. Dementia can be caused by many different medical conditions, such as a severe head injury or major stroke. Other common dementias are Lewy body dementia, Frontotemporal dementia, vascular dementia, and Parkinson's disease dementia (see FCA's fact sheet, Is This Dementia and What Does It Mean?).

Although the cause and progression of AD are not fully understood, increasing evidence shows that the first changes in the brain happen as much as 15 years before symptoms of dementia are exhibited by the person with AD. Certain kinds of brain scans can detect these changes. However, this work is not yet advanced enough for it to be of practical use in predicting who will later develop Alzheimer's disease.



The prevention of Alzheimer's disease is a popular topic in the media. A number of non-medical, life-style practices are recommended for possible prevention, a healthy way to manage the disease, and general age-related well-being. There is evidence, but no documented proof, that mental stimulation (brain games), exercise (like walking, swimming, yoga), social activities, and a healthy diet (fruit, vegetables and foods high in anti-oxidants) may help.

However, there is a great deal of evidence that small strokes are common in people with Alzheimer's disease which only make AD symptoms worse. Given what we know about stroke prevention, maintaining healthy blood pressure, avoiding diabetes or managing it well, keeping cholesterol down, and not smoking are four key things you can do to lower your risk.

This disease can appear as young as age 30, but is typically diagnosed after age 60, and risk of having the disease increases with age. By age 90 as much as -0% of the population may be affected. The genetics of AD are complex and knowledge is changing rapidly. Except for a small percent of families where a single gene causes the disease, having a family member with AD increases your risk only moderately. Alzheimer's disease is reported to be the sixth leading cause of death in the U.S.