Dementia is not something that just happens to everyone as they get older. It is caused by different illnesses.

What is dementia?

Our brains control everything we think, feel, remember and do.

There are diseases that stop a person’s brain from working properly. When a person has one of these diseases, they may have problems thinking, remembering and speaking. They might say or do things that seem strange to others and find it harder to do everyday things. They may not seem like the person they used to be.

When these problems get worse over time, doctors may use the word dementia to describe them.

Why does it happen?

Dementia is not something that just happens to everyone as they get older. It is caused by different diseases.

These diseases affect different parts of the brain, so they affect people in different ways.

Most people with dementia have Alzheimer’s disease or vascular dementia but there are other types too

In most cases we don’t know why a person may get one of these diseases while someone else may not. But we do know there are things we can do to make us less likely to develop dementia. Doctors and scientists are working hard to find out more about dementia – including its causes.

Some people may be more likely to develop dementia than others, like those who have had a stroke, or who have:

  • diabetes
  • high blood pressure
  • high cholesterol
  • depression.

How does dementia affect someone?

Most of us forget things from time to time, like where we left our keys. This does not mean we have dementia. When someone has dementia, symptoms slowly get worse so that they get in the way of daily life.

When people start to get dementia, you might see some of these things happen:

Forgetting recent events, names and faces.

Putting things in the wrong place.

Not being sure about the date or time of day.

Finding it hard to use the right words or understand other people’s words.

Asking the same questions often in a short space of time.

Finding it hard to pay attention or make simple decisions.

Getting lost, mostly in places that are new.

Changes in how someone feels, like becoming sad or easily upset, or losing interest in things.

As dementia gets worse, people may have trouble speaking clearly or telling other people what they need or how they feel. They may find it hard to eat and drink, wash and dress themselves, and go to the toilet without help.

Who is affected by dementia?

Dementia is very common.

Did you know that almost 1 million people in the UK have dementia?

In the UK there are more women with dementia than men.

People over 65 are much more likely to get dementia, but it can affect younger people too.

Is there a cure?

At the moment there are no medicines that can cure dementia. Once a person has dementia, they will have it for the rest of their life. They will also continue to get worse over time.

There are some medicines that can help for a while, by making day-to-day life a little easier. There may also be group activities people can take part in to help them live better with their symptoms. Your doctor can tell you more about these.

Can I stop myself getting dementia?

There is no sure way to stop anyone from getting dementia, but there are things we can do that may make it less likely that we will.

Eat a balanced diet with plenty of fruit and vegetables.

Keep using your brain – through activities or social groups you enjoy.

Don’t smoke.

Keep your weight healthy.

Stay active and try not to spend too long sitting down.

If you have diabetes, keep to your doctor’s advice.

Drink no more than 14 units of alcohol per week.

Ask your doctor to check your heart health, including blood pressure and cholesterol, and follow their advice if they are too high.

Useful contacts

Admiral Nurses offer people with dementia and their families practical advice, support and tips. 0800 888 6678

Alzheimer’s Society provides information, help and local support groups. A translation service is available. 0333 150 3456

Alzheimer Scotland offers support services, information and advice to people in Scotland. 0808 808 3000

This information was updated in November 2022 and is due for review in November 2024. It was written by Alzheimer's Research UK's Information Services team with input from lay and expert reviewers. Please get in touch if you'd like a referenced copy.



Dementia Research Infoline

Want to know more about dementia? Keen to get involved in research projects?

Contact the Dementia Research Infoline:

9am-5pm, Monday to Friday

0300 111 5 111