What is: Dementia?

Dementia is an umbrella term that covers a range of neurodegenerative disorders involving a decline in cognitive functions, such as thinking, remembering and decision-making. Dementia is caused by abnormal changes in the brain, and can vary in severity. Although it tends to affect older adults, it is not a normal part of aging. Everyone loses neurons, or nerve cells, as they grow older, but people with dementia experience loss at a greater rate.

There are many types of dementia, but four seem to be the most typical. The most common form of dementia is Alzheimer’s disease, comprising upwards of 60% of dementia diagnoses. Alzheimer’s disease is caused by abnormal buildup of proteins in the brain, called tau tangles and amyloid plaques. Next, in order of prevalence, are:

  • Vascular dementia, caused by a disruption in the flow of blood and oxygen to the brain.
  • Lewy Body dementia, caused by abnormal deposits of Lewy bodies, or alpha-synuclein proteins, in the brain.
  • Frontotemporal dementia, caused by abnormal amounts or folding of tau and TDP-43 proteins.

Each type of dementia has unique symptoms and neurodegenerative effects, despite dementia often being used as the definitive, all-encompassing term. There are also cases in which someone experiences multiple causes or forms of dementia; those with mixed dementia undergo changes in brain activity associated with multiple types of dementia.

While each form of dementia has its own individual symptoms, there are overlapping symptoms as well. This can make it hard to distinguish between dementia diagnoses. Additionally, other conditions have symptoms similar to those identified with dementia, sometimes resulting in incorrect diagnoses. Generally speaking, however, people with dementia typically have trouble with memory, communication, judgment and social skills. 

Both biological and environmental risk factors can lead to dementia. Things such as age, family history, and race or ethnicity can all increase the risk of dementia. Older adults, those with a family history of dementia and older Black or Hispanic adults are all at higher risk for dementia. Additionally, environmental factors such as smoking and excessive alcohol consumption can also increase the risk of dementia.

It can be difficult to understand dementia and other neurodegenerative conditions when complex scientific vocabulary is used to describe them. In this series of articles, Conversations to Remember hopes to break down the processes behind common forms of dementia and neurodegenerative conditions mistaken for dementia. 


Centers for Disease Control and Prevention. (2019, April 5). What is dementia? Centers for Disease Control and Prevention. Retrieved February 2022, from https://www.cdc.gov/aging/dementia/index.html 

Lewy body dementia. Alzheimer’s Disease and Dementia. (n.d.). Retrieved February 2022, from https://www.alz.org/alzheimers-dementia/what-is-dementia/types-of-dementia/lewy-body-dementia 

Risk factors. Stanford Health Care (SHC) – Stanford Medical Center. (2017, September 11). Retrieved February 2022, from https://stanfordhealthcare.org/medical-conditions/brain-and-nerves/dementia/risk-factors.html 

U.S. Department of Health and Human Services. (n.d.). What is dementia? symptoms, types, and diagnosis. National Institute on Aging. Retrieved February 2022, from https://www.nia.nih.gov/health/what-is-dementia 

What is dementia? Alzheimer’s Disease and Dementia. (n.d.). Retrieved February 2022, from https://www.alz.org/alzheimers-dementia/what-is-dementia