Dementia with Lewy bodies is a common form of dementia estimated to affect more than 100,000 people in the UK.

The term "dementia" describes a loss of mental ability (cognitive impairment) associated with gradual death of brain cells. It's rare in anyone younger than 65.

Symptoms usually develop gradually and become more severe over the course of several years.

Signs and symptoms

People with dementia with Lewy bodies not only experience problems with memory and judgement, like those with Alzheimer's disease, but are also likely to have difficulties with concentration and visual perception (recognising objects and making judgements about where they are in space).

They may experience:

  • slowed movement, stiff limbs, and tremors
  • recurrent visual hallucinations (seeing things that aren't there)
  • sleep disturbances, including sleepiness during the day
  • fainting, unsteadiness, and falls

People with the condition tend to swing from a state of alertness to drowsiness or staring into space. These extreme changes may be unpredictable and happen from hour to hour or day to day.

Read more about the symptoms of dementia with Lewy bodies.

What causes dementia with Lewy bodies?

Dementia with Lewy bodies is caused by deposits of an abnormal protein called Lewy bodies inside brain cells. These deposits, which are also found in people with Parkinson’s disease, build up in areas of the brain responsible for things such as memory and muscle movement.

It's not clear why the deposits develop and how exactly they damage the brain, but it's thought they disrupt the brain's normal functions by interfering with chemical signals transmitted from one brain cell to another.

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

Diagnosing dementia with Lewy bodies

If you think you may have early symptoms of dementia, it's a good idea to see your GP. If you're worried about someone else, encourage them to make an appointment, and perhaps suggest that you go along with them.

Your GP can do some simple checks to see if there is chance you could have dementia, and they can refer you to a memory clinic or another specialist clinic if necessary.

At one of these clinics, you will be asked about your symptoms and have a physical check-up and memory test. You may also have blood tests and brain scans.

The results of these checks and tests will give your doctor a good idea as to whether your symptoms are caused by dementia with Lewy bodies, another type of dementia, or something else entirely.

Read more about how dementia with Lewy bodies is diagnosed.

How dementia with Lewy bodies is managed

There is no cure for dementia with Lewy bodies or any medication that will slow it down.

However, a few different medicines can be effective in controlling some of the symptoms. In particular, acetylcholinesterase inhibitors (used to treat Alzheimer's disease) have been shown to improve symptoms such as hallucinations and confusion in some people.

Supportive treatments – such as physiotherapy, occupational therapy, and speech and language therapy – can help improve any problems with movement, everyday tasks, and communication.

Psychological therapies and specific dementia activities, such as memory cafés, can also help with memory loss, confusion, and feelings of disorientation.

Read more about treating dementia with Lewy bodies


How quick dementia with Lewy bodies progresses varies from person to person. Home-based help will be needed, and some people will eventually need residential care in a nursing home.

The average survival after the time of diagnosis is similar to that of Alzheimer's disease – around five to eight years. However, as with Alzheimer's disease, this can be highly variable.

If you or a loved one has been diagnosed with dementia, remember that you are not alone. The NHS, social services, and voluntary organisations will be able to provide advice and support to help you and your family.

More information

Living with dementia

Find dementia activities near you

Living well with dementia 

Staying independent with dementia 

Dementia activities 

Looking after someone with dementia 

Dementia and your relationships 

Communicating with people with dementia 

Coping with dementia behaviour changes 

Care and support

Sources of help and support 

Organising care at home 

Dementia and care homes 

Dementia, social services, and the NHS 

Dementia and your money 

Managing legal affairs for someone with dementia 

End of life planning 

How you can help

Share your dementia experiences

Page last reviewed: 22/01/2015

Next review due: 22/01/2017