What Is the Difference Between Alzheimer's and Dementia?

Although the terms dementia and Alzheimer's disease are sometimes used interchangeably, they are not synonyms. Dementia is actually a group of symptoms such as memory loss and other problems with cognition and communications. Alzheimer's is the most common type of dementia, representing at least half of cases. Dementia can also be caused by Parkinson's disease, Huntington's disease, and other diseases that affect the brain.