Alzheimer's disease (AS) is a form of dementia, is a progressive, degenerative brain disease. It impairs memory, thinking, and behavior. Memory impairment is a required symptom for the diagnosis of this or any type of dementia. Change in one of the following areas must also be present: language, decision-making ability, judgment, attention, and other areas of mental function and personality.
The rate of progression is different for each person. If AD develops rapidly, it is likely to continue to progress rapidly. If it has been slow to progress, it will likely continue on a slow course. The cause of AD is not entirely known but is thought to include both genetic and environmental factors. A diagnosis of AD is made based on characteristic symptoms and by excluding other causes of dementia.
