What is Alzheimer’s?
Alzheimer’s (AHLZ-high-merz) disease is a progressive brain disorder that gradually destroys a person’s memory and ability to learn, reason, make judgments, communicate and carry out daily activities. As Alzheimer’s progresses, individuals may also experience changes in personality and behavior, such as anxiety, suspiciousness or agitation, as well as delusions or hallucinations. There are now more than 5 million people in the United States living with Alzheimer’s disease. This number includes 4.9 million people over the age of 65 and between 200,000 and 500,000 people under age 65 with early-onset Alzheimer’s disease and other dementias.
Alzheimer’s is the most common form of dementia, a group of conditions that all gradually destroy brain cells and lead to progressive decline in mental function. Vascular dementia, another common form, results from reduced blood flow to the brain’s nerve cells. In some cases, Alzheimer’s disease and vascular dementia can occur together in a condition called “mixed dementia.” Other causes of dementia include frontotemporal dementia, dementia with Lewy bodies, Creutzfeldt-Jakob disease and Parkinson’s disease. See Related Diseases for more information.
Progression of Alzheimer’s disease
Alzheimer’s disease advances at widely different rates. People with Alzheimer’s die an average of four to six years after diagnosis, but the duration of the disease can vary from three to 20 years. The areas of the brain that control memory and thinking skills are affected first, but as the disease progresses, cells die in other regions of the brain. Eventually, the person with Alzheimer’s will need complete care. If the individual has no other serious illness, the loss of brain function itself will cause death. For more information, please see Stages.
Early-stage and early-onset Alzheimer’s
Early-stage is the early part of Alzheimer’s disease when problems with memory, thinking and concentration may begin to appear in a doctor’s interview or medical tests. Individuals in the early-stage typically need minimal assistance with simple daily routines. At the time of a diagnosis, an individual is not necessarily in the early stage of the disease; he or she may have progressed beyond the early stage.
The term early-onset refers to Alzheimer’s that occurs in a person under age 65. Early-onset individuals may be employed or have children still living at home. Issues facing families include ensuring financial security, obtaining benefits and helping children cope with the disease. People who have early-onset dementia may be in any stage of dementia – early, middle or late.
(c)2007 Alzheimer’s Association. All rights reserved.