What is the difference between Alzheimer’s disease and dementia? This is one of the most common questions I receive when I give presentations in the community or answer the U-M Memory Connection line. This is a great question because the terms are often used in place of one another, despite the fact that they mean different things.
In brief, dementia is a broad term used to describe a collection of symptoms. The symptoms are caused by changes in brain function and they are severe enough to affect daily functioning. There are many reasons why someone may have dementia. Alzheimer’s disease accounts for approximately 75% of dementia cases, and that is why the words are often used interchangeably.
I like to use the following visual images when illustrating the difference:
- Imagine that the fruit bowl in your kitchen is dementia. While there are several different pieces of fruit in the bowl, the fruit found most frequently, perhaps a banana, is Alzheimer’s disease. The other fruits in the bowl represent other causes of dementia that aren’t quite as common, such as vascular dementia, Lewy body dementia, frontotemporal dementia, or reversible dementias induced by things like a urinary tract infection or a vitamin deficiency.
- Imagine that your grandchild has a runny nose. Their runny nose is not a specific disease or condition; it is just a symptom. There are many different potential reasons for the runny nose. It may be caused by influenza, a sinus infection or a reaction to being outside in a cold temperature for too long. In the same way, dementia is not a specific disease and there are several reasons a person may exhibit dementia, the most common of which is Alzheimer’s disease.