Alzheimer's disease is a degenerative disorder of the brain and one of several conditions that cause dementia, a progressive decline of mental functions resulting in memory loss and confusion.
It is estimated that about 4 million North Americans have the disease and that Alzheimer's is responsible for 50 percent to 70 percent of all cases of dementia.
The cause of Alzheimer's is unknown but doctors are making progress in understanding and diagnosing the disease and developing drug treatments that may slow the decline. Most researchers believe that the cause may be a complex set of factors, including:
Alzheimer's patients also may undergo changes in behavior, experiencing agitation, anxiety and hallucinations.
The first symptom tends to be memory lapses, especially for recent events or newly learned information. Memory lapses may be very subtle at first, but leads to more significant gaps and confusion. Eventually, the disease leads to severe brain damage that impairs a person's ability to complete everyday tasks as well as to reason, learn and imagine.
People with Alzheimer's experience difficulties communicating, learning, thinking and reasoning -- problems severe enough to impact their work, social activities and family life.
One of the most common early signs of dementia is memory loss, forgetting information that has been recently learned. While it can be normal to forget appointments, names or telephone numbers, individuals with dementia have more severe deficits in memory. They often find it hard to complete everyday tasks that are so familiar that most people ordinarily wouldn't think twice about how to do them. Alzheimer's disease may cause a person to forget how to prepare a meal, use a household appliance or to participate in a lifelong hobby.
There is no cure for Alzheimer's disease. Available treatments offer relatively small symptomatic benefit but remain palliative in nature. They include pharmaceutical, psychosocial and caregiving treatments.