DementiaRoadmap Wales

Promoting living well with dementia across Wales

What causes dementia?

April 6 2014

Dementia is the result of brain cells being damaged in an ongoing way. This happens as a result of a number of different diseases, sometimes referred to as ‘types’ of dementia. It is not an inevitable part of ageing.

Some of the more common diseases that cause dementia include:

  • Alzheimer’s disease (62%): A physical disease caused by changes in the structure of the brain and a shortage of important chemicals that help with transmission of messages.
  • Vascular dementia (17%): Caused by problems in the supply of blood to the brain, commonly cause by a stroke or a series of small strokes.
  • Mixed dementia (10%): A type of dementia where a person has a diagnosis of both Alzheimer’s disease and vascular dementia.
  • Dementia with Lewy bodies (4%): One of the less common forms of dementia, it is caused by irregularities in brain cells. Leading to symptoms similar to Alzheimer’s disease and Parkinson’s disease.
  • Rarer causes of dementia (3%): There are many rarer causes diseases and syndromes that can lead to dementia or dememtia-like symptoms, including Corticobasal degeneration and Creutzfeldt-Jakob disease.
  • Fronto-temporal dementia (2%): rare when all ages are taken into account but relatively common in people under 65, it is a physical disease that affects the brain. [1]

Other less common causes of dementia are:

  • Huntington’s disease
  • Creutzfeldt-Jakob Disease (CJD)
  • AIDS related dementia
  • Korsakoffs Syndrome

The term ‘Mixed’ is used when dementia has more than one cause. For example a person may have both Alzheimer’s disease and Vascular dementia.


1. Dementia 2013 infographic – text only version

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