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What is dementia

It's normal for your memory to be affected by stress, tiredness, certain illnesses and medicines. But if you're becoming increasingly forgetful, particularly if you're over the age of 65, it's a good idea to talk to a GP about the early signs of dementia.

Memory loss (amnesia) can be annoying if it happens occasionally, but if it's affecting your daily life, or it's worrying you, or someone you know, you should get help from a GP.

Dementia is not only about memory loss. It can also affect the way you speak, think, feel and behave.

It's also important to remember that dementia is not a natural part of ageing.

Dementia is a syndrome (a group of related symptoms) associated with an ongoing decline of brain functioning. There are many different causes of dementia, and many different types. 

People often get confused about the difference between Alzheimer's disease and dementia. Alzheimer's disease is a type of dementia and, together with vascular dementia, makes up the majority of cases.

Symptoms of dementia

Dementia symptoms may include problems with:

  • memory loss
  • thinking speed
  • mental sharpness and quickness
  • language, such as using words incorrectly, or trouble speaking
  • understanding
  • judgement
  • mood
  • movement
  • difficulties doing daily activities

People with dementia can lose interest in their usual activities, and may have problems managing their behaviour or emotions.

They may also find social situations difficult and lose interest in relationships and socialising

Aspects of their personality may change, and they may lose empathy (understanding and compassion).

A person with dementia may see or hear things that other people do not (hallucinations and hearing voices).

Because people with dementia may lose the ability to remember events, or not fully understand their environment or situations, it can seem as if they're not telling the truth or are wilfully ignoring problems.

As dementia affects a person's mental abilities, they may find planning and organising difficult. Maintaining their independence may also become a problem.

A person with dementia will usually need help from friends or relatives, including help with making decisions.

The symptoms of dementia usually become worse over time. In the late stage of dementia, people will not be able to take care of themselves and may lose their ability to communicate.

Read more about the symptoms of dementia.

Why it's important to get a diagnosis

Although there is no cure for dementia at the moment, an early diagnosis means its progress can be slowed down in some cases, so the person may be able to maintain their mental function for longer.

A diagnosis helps people with dementia get the right treatment and support. It can also help them, and the people close to them, to prepare for the future.

With treatment and support, many people are able to lead active, fulfilled lives with dementia.

Read more about how dementia is diagnosed.

How common is dementia

Research shows there are more than 944,000 people in the UK who have dementia. 1 in 11 people over the age of 65 have dementia in the UK.

The number of people with dementia is increasing because people are living longer. It is estimated that by 2030, the number of people with dementia in the UK will be more than 1 million.

Further information:

Sign up for Dementia Information Service emails.

Page last reviewed: 20 July 2023
Next review due: 20 July 2026

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