Dementia is a word used to describe a group of symptoms that occur when brain cells stop working properly. There are a number of diseases that cause dementia.

Alzheimer’s disease is the most common cause of dementia, but there are other types of dementia too. It is possible to have more than one type of dementia at the same time. Alzheimer’s is sometimes seen with vascular dementia or dementia with Lewy bodies. You might hear this called ‘mixed dementia’.

Page last reviewed: 05/07/2018

Source: Types of dementia; Alzheimer’s disease. Alzheimer’s Research UK website

Source: NICE Clinical Knowledge Summaries; Dementia; Causes. National Institute for Clinical Excellence website

Source: NICE Clinical Knowledge Summaries; Dementia; Causes. National Institute for Clinical Excellence website

Source: Types of dementia; Frontotemporal dementia. Alzheimer’s Research UK website

Although often thought of as a disease of older people, around 4% of people with Alzheimer’s are under 65. This is called early-onset or young-onset Alzheimer’s. It usually affects people in their 40s, 50s and early 60s.

Source: Prince, M et al (2014) Dementia UK: Update Second Edition report produced by King’s College London and the London School of Economics for the Alzheimer’s Society

Source: Types of dementia; Alzheimer’s Disease; Early-onset Alzheimer’s disease. Alzheimer’s Research UK website