Patient information from BMJ

Alzheimer's disease and other kinds of dementia

Last published:Nov 16, 2023

Many of us start to forget things as we get older. But for people with Alzheimer’s disease or another type of dementia, this forgetfulness becomes very bad. The symptoms get worse over time.

What is dementia?

Dementia is a term doctors use to describe what happens when certain parts of the brain stop working properly. The most common type is called Alzheimer's disease.

Other common types of dementia are vascular dementia, which can happen when small blood vessels in or near the brain are damaged, and Lewy body dementia.

Dementia is an illness. It's not a normal part of getting older. But dementia is more common in older people. It's rare for younger people to get dementia.

What are the symptoms?

The symptoms of dementia usually come on gradually, although they can start very suddenly in people who have had a stroke (damage to the brain due to part of the blood supply being cut off). The first sign of dementia is usually mild forgetfulness. Other symptoms include:

• getting lost or confused easily

• forgetting how to do important, everyday things, such as cooking meals, getting dressed, or using the toilet. This can make it very hard for someone with dementia to look after themselves

• having trouble sleeping

• not being able to recognise even close family members.

The problems someone gets because of dementia can make it seem as if that person's personality has changed. For example:

• they might become agitated or moody, pace about, or wander off

• they might have trouble talking or understanding you

• some people imagine that things are happening to them (this is called having delusions) or see things that aren't really there (hallucinations). This can be upsetting. For example, someone might think that people are trying to hurt them or steal their things

• they might become aggressive.

What will happen?

There is no cure for Alzheimer's disease and most other kinds of dementia. But there are medicines that might help a little with forgetfulness and confusion.

To read about treatments, see the leaflet Alzheimer's disease and other types of dementia: what treatments work?

It's hard to know how quickly someone's symptoms will get worse. Some people stay the same for a long time. Others have good days and bad days. Eventually most people with dementia need help with everyday things like getting washed and dressed.

People with mild dementia might wish to plan for the future and discuss their treatment with relatives. Some people write down what types of care they would prefer and how they would like to be looked after for their relatives or carers to refer to later on. This is called advance directive.

People with dementia can lose the ability to keep track of money. So it's important to decide who should help with decisions about money and health care.

Where to get more help

If you have been recently diagnosed with dementia, or if you are caring for someone with dementia, make sure you get all the help you can: for example, from your family, and social services.

There are also local carers' groups that may be able to give you support.

For example, in the UK, you can contact the Alzheimer's Society (alzheimers.org.uk ), Alzheimer Scotland (alzscot.org ), and Carers UK (carersuk.org ). Your doctor will also be able to suggest where you can go for help in your area.