There are a large number of underlying conditions which cause the symptoms of dementia, as a result of changes that happen in the brain and the ultimate loss of nerve cells (neurons). The most common causes are:
- Alzheimer’s disease
- Vascular dementia
- Dementia with Lewy bodies
- Fronto-temporal dementia (including Pick’s disease)
The boundaries between the different types are not necessarily distinct. Alzheimer’s disease and vascular dementia are responsible for up to 90% of cases of dementia.