Dementia with Lewy bodies (DLB), also known as Lewy body dementia, is one of the most common types of dementia.

Dementia is the name for problems with mental abilities caused by gradual changes and damage in the brain. It's rare in people under 65.

It tends to develop slowly and get gradually worse over several years.

People with dementia with Lewy bodies may have:

• hallucinations and hearing voices – seeing, hearing or smelling things that are not there
• problems with understanding, thinking, memory and judgement – this is similar to Alzheimer's disease, although memory may be less affected in people with dementia with Lewy bodies
• confusion or sleepiness – this can change over minutes or hours
• slow movement, stiff limbs and tremors (uncontrollable shaking)
• disturbed sleep, often with violent movements and shouting out
• fainting spells, unsteadiness and falls
• depression and anxiety

These problems can make daily activities increasingly difficult and someone with the condition may eventually be unable to look after themselves.

Read more about the symptoms of dementia with Lewy bodies

See a GP if you think you have early symptoms of dementia, especially if you're over 65 years of age.

If you're worried about someone else, encourage them to make an appointment with a GP and perhaps suggest that you go with them.

The GP can do some simple checks to try to find the cause of your symptoms and they can refer you to a memory clinic or another specialist for further tests if needed.

Read more about getting a dementia diagnosis

There's no single test for dementia with Lewy bodies.

The following may be needed to make a diagnosis:

• an assessment of symptoms – for example, whether there are typical symptoms of dementia with Lewy bodies
• an assessment of mental abilities – this will usually involve a number of tasks and questions
• blood tests to rule out conditions with similar symptoms
• brain scans, such as an MRI scan, CT scan or a SPECT scan – these can detect signs of dementia or other problems with the brain

Read more about the tests used to diagnose dementia

There's currently no cure for dementia with Lewy bodies or any treatment that will slow it down.

But there are treatments that can help control some of the symptoms, possibly for several years.

Treatments include:

• medicines to reduce hallucinations, confusion, drowsiness, movement problems and disturbed sleep
• therapies such as physiotherapy, occupational therapy and speech and language therapy for problems with movement, everyday tasks and communication
• psychological therapies, such as cognitive stimulation (activities and exercises designed to improve memory, problem solving skills and language ability)
• activities for dementia, such as memory cafes (drop-in sessions for people with memory problems and their carers to get support and advice)

Read more about how dementia with Lewy bodies is treated

How quickly dementia with Lewy bodies gets worse varies from person to person.

Home-based help will usually be needed, and some people will eventually need care in a care home.

The average survival time after diagnosis is around 5 to 7 years. But this is highly variable and some people live much longer than this.

If you or a loved one has been diagnosed with dementia, remember that you're not alone. The NHS and social services, as well as voluntary organisations, can provide advice and support for you and your family.

Dementia with Lewy bodies is caused by clumps of protein forming inside brain cells. These abnormal deposits are called Lewy bodies.

These deposits are also found in people with Parkinson's disease, and they build up in areas of the brain responsible for functions such as thinking, visual perception and muscle movement.

It's not clear why the deposits develop and how exactly they damage the brain. It's thought that part of the problem is the proteins affecting the brain's normal functions by interfering with signals sent between brain cells.

Dementia with Lewy bodies usually occurs in people with no family history of the condition, although there have been very rare cases that seem to run in families.

Living with dementia

• Activities for dementia
• Living well with dementia
• Staying independent with dementia
• Looking after someone with dementia
• Dementia and relationships
• Communicating with someone with dementia
• Coping with dementia behaviour changes

Care and support

• Help and support
• Dementia and care homes
• Dementia, social services and the NHS
• Dementia and managing money
• Managing legal affairs for someone with dementia
• End of life planning

How you can help

• Share your dementia experiences on the Alzheimer's Society website