Like all parts of the body, brains sometimes become ill. There are illnesses that stop a person's brain from working properly.
When a person has one of these illnesses, their brain starts to have problems doing all the jobs it has to do.
The person may start to have problems with remembering, thinking, speaking or seeing what or where things are. They might say or do things that seem strange to us. They may find it more difficult to do everyday things. They may not seem like the same person they used to be.
Doctors use the word dementia to describe these different problems.

Questions
- What is dementia?
- Which illnesses cause dementia?
- Who gets dementia?
- Will I get dementia?
- What happens to someone with dementia?
- Why do people with dementia change so much?
- Why do simple things become difficult for people with dementia?
- What does it feel like to have dementia?
- Can a person with dementia get better?
- What can I do?
- What if things go wrong?
- How can I cope with my feelings?
- Tell us what you think
This information was updated in November 2021 and is due for review in November 2023. Please contact us if you would like a version with references.