There's a common misconception that dementia is synonymous with Alzheimer’s disease. While dementia is the primary symptom of Alzheimer’s disease, and Alzheimer's is the most prevalent cause of dementia, the two terms aren't interchangeable. Simply stated, Alzheimer's is a disease, where as dementia is a symptom. Without an evaluation from a qualified healthcare professional, it may be nearly impossible to tell the difference between dementia from other causes and Alzheimer's disease, but it's an important distinction to make in order to determine the proper treatment. There are a few key differences that can help indicate the true nature of the affliction.
Dementia. The Mayo Clinic explains, "Dementia describes a group of symptoms affecting intellectual and social abilities severely enough to interfere with daily functioning." There are essentially two types of dementia—one affects memory and speech, and the other affects behavior and attention span. Dementia may be caused by a number of different diseases, or from certain types of medication, other medical issues such as stroke or long-term substance abuse. In order to be considered dementia, there has to be noticeable issues with at least two types of cognitive function—for instance, memory recall and language. Impairment in only one area isn't dementia, and other causes should be identified.
Alzheimer's disease. In the early stages of Alzheimer's disease, dementia may be the only recognizable symptom. In those early stages, it may be impossible to determine whether the affliction is dementia or Alzheimer's disease, especially if there are no other apparent causes for the dementia. However, Alzheimer's disease will continue to get worse over time, and will affect more and more parts of the brain. Late-stage Alzheimer's patients may get to the extreme of being unable to read or write, unable to remember even the most basic things, such as where they live or how to get dressed, and may even lose the ability to speak altogether. Emerging technology may eventually allow doctors to definitively diagnose Alzheimer's disease with brain scans, but for now, the tangled neurons that result from the disease can only be observed through a microscope with post-mortem samples.