Dementia: At a glance

What is dementia?

Dementia is not an inevitable part of ageing and is not a disease in its own right. It is an umbrella term. Use this page to find out more about how it affects people across the United Kingdom.

It describes the symptoms that occur when the brain is affected by certain diseases or conditions that cause the gradual death of brain cells. This leads to progressive cognitive decline.

How fast cognitive decline progresses will vary from person to person and may depend on which type of dementia they have. Symptoms include:

  • loss of memory
  • changes in behaviour and mood
  • problems wih communication and reasoning skills.

This Alzheimer’s Society video explains what dementia is, how it affects the brain and how it might affect a person with the disease.

There are many different types of dementia. The most common are:

For more information on the above, see Early signs of dementia.

Experiencing dementia from the inside

View the full video

Who does dementia affect?

More than 920,000 people in the UK are living with dementia – a number expected to rise to over a million by 2024 (Alzheimer’s Society, 2019).

The vast majority of people with dementia are aged 65 and over, accounting for over 880,000 people. However, an estimated 40,000 people under 65 are living with dementia in the UK (Alzeimer's Society, 2014).

Figures published by the Alzheimer’s Society, Alzheimer’s Research UK, Public Health England and WHO show that:

According to Alzheimer’s Disease International, the total estimated worldwide cost of dementia was US $1 trillion in 2018. If dementia care were a country, it would be the world’s 18th largest economy . If dementia care were a company, it would be the world’s largest by annual revenue exceeding Apple, Google and Exxon.

Key UK statistics

National dementia strategies

Oversight of social care and aspects of healthcare are devolved in the UK with separate dementia strategies for England, Wales, Scotland and Northern Ireland.

Each strategy has one central objective – to provide better care and support for people with dementia and their families.