The Alzheimer's Society estimates that there are currently over 700,000 people in the UK with dementia. This steady increase reflects the worldwide picture of dementia. There are currently nearly 18 million people with dementia in the world. This is set to rise to around 34 million by 2025.
Dementia primarily affects older people.
While it is estimated that there are around 18,500 people under the age of 65 with dementia in the UK, the chances of having the condition rise sharply with age. This compares to one in five among those over 80. But dementia is not an inevitable consequence of old age. Most 90 year olds, for example, do not have the condition. Determining the incidence of each of the different types of dementia is not a straightforward task.