What is dementia?

4. Who gets dementia?

There are currently around 850,000 people in the UK with dementia. It mainly affects people over the age of 65 (one in 14 people in this age group have dementia), and the likelihood of developing dementia increases significantly with age. However, dementia can affect younger people too. There are more than 42,000 people in the UK under 65 with dementia.

Scientists are investigating how dementia might run in the family. In a very small number of people, certain types of dementia are inherited as a single gene that directly causes the disease. People with one of these genes will usually get dementia before the age of 65. Everyone else will inherit a combination of genes that increases or decreases their risk of developing dementia in much less direct ways.

For more information see Genetics of dementia. For more information about dementia in people under 65 see factsheet Young-onset dementia.