Dementia is an umbrella term that describes a group of symptoms that are caused by many diseases that affect the brain, such as Alzheimer’s disease or stroke. The World Health Organisation (WHO) defines dementia as a syndrome of chronic or progressive nature in which there is deterioration in cognitive function beyond what might be expected from normal ageing. Dementia affects thinking, memory, orientation, learning capacity, language, and judgement. The impairment in cognitive function is commonly accompanied, and occasionally preceded, by weakening of emotional control and motivation as well as deterioration of social behaviour.
Dementia is a common condition and the risk of developing dementia increases as you get older, with the condition most frequently occurring in people over the age of 65, with the likelihood of developing dementia roughly doubling every five years. Currently there are estimated to be 850,000 people in the UK living with Dementia. Figure 1 shows UK prevalence of dementia for 65+ age groups.
As dementia affects a person’s mental abilities, maintaining their independence can become a problem. Most types of dementia can’t be cured, but if it is detected early there are ways you can slow it down and maintain mental function.
 WHO: Dementia – Fact Sheet, updated May 2017. Available from: http://www.who.int/mediacentre/factsheets/fs362/en/
 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
Figure 1: Dementia prevalence in the UK by age and sex, 2014.
Increasing life expectancy means that the number of people with dementia in the UK is expected to grow rapidly
Figure 2: Predicted growth in Dementia prevalence in the UK.
Not everyone living with Dementia has a formal diagnosis for the condition. The national Dementia diagnosis rate for people aged 65+ is estimated to be 68.7%. There is a considerable economic cost associated with the disease estimated at £23 billion a year, which is predicted to triple by 2040. This is more than the cost of cancer, heart disease and stroke.
 NHS Digital. Dementia 65+ estimated diagnosis rate. November 2017 (accessed December 2017) https://app.powerbi.com/view?r=eyJrIjoiYjE1Y2FiNzUtYmMwNy00ODg1LWFlMTgtODFmZTg0MzhiZDc1IiwidCI6IjgwN2YyZjMwLWNhOGMtNDE5Zi1hMTc5LTVjNGZjN2E0YmY2YiIsImMiOjN9
 NHS England digital. https://www.england.nhs.uk/mental-health/dementia/ (accessed December 2017)