Alzheimer's vs Dementia: What’s the Difference?

Posted on May 6, 2019

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Sometimes, people use the terms “Alzheimer’s” and “dementia” interchangeably. But these words actually have different meanings. While there is a relationship between Alzheimer’s disease and dementia, there are key differences that are important to understand. Here’s an introduction to these often confused terms.

Dementia
Put simply, dementia is a nonreversible decline in mental function. It is not a disease, but instead a group of symptoms that commonly include problems with memory, thinking, problem solving, language and perception. Dementia is a general term for a number of diseases that impair memory function or reasoning. In fact, over 100 diseases can cause dementia, including Parkinson’s Disease, HIV, and Huntington’s Disease. Some other common causes of dementia include:

• Vascular dementia, where a lack of oxygen to the brain, such as after a stroke, causes nerve cells to die.
• Dementia with Lewy bodies, where abnormal structures called Lewy bodies form in the brain and cause the death of nerve cells.
• Frontotemporal dementia, where clumps of abnormal protein form in the brain and cause the death of nerve cells.
• Mixed dementia, where someone has more than one type of dementia and a mix of symptoms.

Treatments for dementia will depend on the cause. In most cases, individuals will benefit from supportive services such as home health aides, assisted living facilities, or nursing homes.

Alzheimer’s Disease
While there are many diseases that cause dementia, Alzheimer’s is the most common form, accounting for an estimated 50 to 70 percent of all dementia cases. Alzheimer’s is a physical disease in which abnormal structures called ‘plaques’ and ‘tangles’ build up inside the brain. Common symptoms include:

• Memory loss that disrupts daily life
• Difficulty completing familiar tasks
• Confusion with time and place
• Trouble understanding visual images or spacial relationships
• Problems with speaking and writing
• Changes in mood and personality

As Alzheimer’s disease progresses, the individual will require more support from caregivers to complete basic daily tasks. Although there is currently no cure for Alzheimer’s and it is considered a terminal illness, there are treatments that aim to ease symptoms or slow the disease’s progression.

A Normal Part of Aging?
While there are exceptions, dementia is generally considered a late-life disease because it tends to develop mostly in elderly people. About five to eight percent of all people over the age of 65 have some form of dementia, and it is estimated that as many as half of people 85 or older have dementia. Still, it is important to recognize that Alzheimer’s Disease and other forms of dementia are not a part of normal aging. While age-related memory difficulties are completely normal, memory loss that disrupts daily life may be a symptom of Alzheimer’s or another type of dementia. For more information about typical age-related changes vs. dementia symptoms, the Alzheimer's Association website is a great place to start.