Lewy Body Dementia

Cristina Po Wenger
Author: Cristina Po Wenger Medical Reviewer: Amy Shelby Last updated:

Lewy body dementia, which is also known as dementia with Lewy bodies, is a condition that generally occurs in older people and impacts a person’s feelings, behavior, ways of thinking, and movement. 

Lewy body disease is one of the most common types of dementia but as yet, there is no treatment for it and no way to avoid developing it. In the advanced stages of this condition, people often require a comprehensive care package to be able to live their lives. [1] [2]

What is Lewy body dementia?

Lewy body dementia is a cognitive disorder named after Friedrich H. Lewy, a German-American scientist who discovered the ‘Lewy bodies’ that cause symptoms of dementia including memory loss and movement difficulties. Lewy bodies are unusual build-ups of a particular protein called alpha-synuclein, making it difficult for the neurons in the brain to carry messages to the rest of the brain and the body as they usually would. 

One neurotransmitter that is particularly affected by these Lewy bodies – acetylcholine – is the one that is primarily responsible for memory and learning. This is why people with Lewy body dementia often struggle to remember things or retain information in the ways they had previously. [3]

Symptoms of Lewy body dementia

Lewy body dementia has a range of symptoms that can impact somebody’s thinking or cognitive processing, the way they move their body, how they feel, their mental health, and their nervous system and autoregulation. 

You don’t have to have all of these symptoms to have Lewy body dementia, and some of them are very similar to other conditions like Parkinson’s disease, Alzheimer’s disease and some mental health problems, so it is often misdiagnosed.


Many of the symptoms of Lewy body dementia impact people’s sleeping patterns but the way this happens varies from person to person. Some people feel sleepy more of the time than they typically would, while others suffer from insomnia. 

Some people have very disturbed sleeping patterns, which can be caused by restless leg syndrome, or can begin to act out their dreams while asleep, which can pose a risk to those around them.


People with Lewy body dementia often find that their physical movement patterns change. Some people experience stiffness in their arms and legs or feeling like their muscles are very rigid. Either as a separate symptom or because of this, some people with this condition will move very slowly or even appear stuck because they feel like they can’t move.

If you know someone who might have Lewy body dementia, watch out for the signs below, as well as any change in their handwriting, a change in their posture (becoming more doubled over), any struggle to speak, fewer facial expressions, or any difficulty swallowing food and drink.

Similarities between Lewy Body Dementia and Parkinson’s Disease

The following movement symptoms are often confused with Parkinson’s disease, particularly if the person has a slight tremor or shakes even when the rest of their body is still, if they struggle with hand eye coordination, or begin to walk in a shuffle. 

Many of these movement symptoms can also lead to a greater risk of falling. To confuse diagnosis further, as many as 78 percent of people with Parkinson’s disease also have dementia. [4] 


Because of the impact Lewy body dementia has on neurotransmitters in the brain, the body often struggles to regulate its functions in the way it ordinarily would. A good example of this is that someone’s temperature might change dramatically, going from very hot and sweating to shivery and cold, so they also feel very sensitive to the temperature in the room they are in.

A person with Lewy body dementia might also struggle with changes in their blood pressure. This can mean they are prone to dizziness or fainting when they stand up after sitting down for some time, which is another reason they are at risk of falls.

Other symptoms related to autoregulation include urinary incontinence and constipation.

Mental health

Similarities between Lewy body dementia and psychosis

Many symptoms of Lewy body dementia can be confused with symptoms of severe mental illnesses, like psychosis, and other issues with the brain. For example, 80 percent of people with Lewy body dementia experience visual hallucinations and some have other sensory hallucinations, which are a very common symptom of psychosis and schizophrenia. [5]

Other similarities include: 

  • The person’s thoughts and ideas might seem very jumbled and disorganized.
  • They might make dangerous decisions.
  • They could become confused about where they are and what day or year it is.
  • They could feel very paranoid, for example, about people watching them, or have delusions about the world and themselves, like thinking that they have special powers.

Similarities between Lewy body dementia and other mental health problems

People with Lewy body dementia might also experience generally poor mental health, including having symptoms of depression or anxiety and seeming very agitated. 

Causes of Lewy body dementia

There is no definitive answer about what causes Lewy body dementia but some factors, including genetics and other health conditions, can mean there is a greater predisposition to developing it. 

There is also no particular trigger for the onset of Lewy body dementia. It gradually worsens over time, usually between five to eight years, but can happen more rapidly, or in some cases take up to 20 years.

People at greater risk of developing Lewy body dementia include those who are related to people who have been diagnosed with the condition, people over 50, and those with other conditions like Parkinson’s disease. 

There is not a huge difference in the likelihood of developing it between men and women, although women are more likely to develop Lewy body dementia alongside Alzheimer’s disease, and men are more likely to develop it alongside Parkinson’s disease. [6]

There is some research that shows thata person’s genetics might play a role in their likelihood of developing Lewy body dementia, but in conjunction with their age and other risk factors. The same gene that is linked with the development of Alzheimer’s disease might play a role, as might another gene that is related to Parkinson’s disease; however, genetic changes causing Lewy body dementia are still very rare. [7] Research into what causes Lewy body dementia is ongoing.

Diagnosing Lewy body dementia

Diagnosing Lewy body dementia can be a complex process and many people are misdiagnosed before they get the right diagnosis. Two closely related conditions are dementia with Lewy bodies and Parkinson’s disease dementia. 

Dementia with Lewy bodies tends to first become apparent through cognitive symptoms, or the impact on somebody’s mental processing and ways of thinking first, with movement related symptoms then developing at least a year later.

With Parkinson’s disease dementia, the impact on someone’s movement is the first set of symptoms, with cognitive decline then developing more than a year afterwards.

It is important to note that not everyone who has Parkinson’s disease has dementia, particularly if they are younger and have early onset Parkinson’s; however, the majority of people with Parkinson’s disease do have dementia. Clinicians often misdiagnose Lewy body dementia as Parkinson’s or Alzheimer’s disease first, due to the crossover in symptoms. [8]

Who is involved in diagnosis?

Because diagnosing this condition is so complex, a range of medical professionals are often involved in the assessment process. This could include:

  • A psychiatrist, to work with someone to determine their mental health symptoms and the impact they are having on their life, as well as to rule out a psychiatric condition like schizophrenia.
  • A geriatrician, to look at the general symptoms related to a person’s age, if they are over 60, and to work out what care package they might need.
  • A neurologist, to examine cognitive symptoms and functioning, including any impact on the nervous system and autoregulation.

How clinicians rule out other conditions

Clinicians are sometimes hesitant to give a definitive diagnosis of Lewy body dementia if someone is in the early stages of developing symptoms, so they might say it is ‘likely’ Lewy body dementia and then continue to monitor the person.

For someone to be given a probable diagnosis, they need to be experiencing two of any of the following symptoms:

  • Unusual behavior and thought patterns
  • Hallucinations
  • Issues with sleep
  • Motor symptoms like tremors, muscle rigidity and slowness

If the person is only experiencing one of these things, their clinician is likely to say it is possible they have Lewy body dementia, but further tests and observation are necessary. 

What to expect when seeking a diagnosis of Lewy body dementia

When you visit a clinician to seek a diagnosis of dementia, they will ask you about your presenting symptoms and the impact that they are having on your everyday tasks. They will also ask you about your medical history – any other conditions you have and your family’s medical history.

To work out whether you have Lewy body dementia and rule out other possible diagnoses, your doctor will also ask you to do some tests. Depending on your symptoms, these might include blood tests, scans like an MRI or CT, a neurological test, or participation in a sleep study.

Even if you are not completely sure that you have Lewy body dementia, if you are experiencing any of its associated symptoms, try to see your doctor as soon as you can. Delays in diagnosis of this condition can impact your life expectancy.

Treatment for Lewy body dementia

There is no known cure for Lewy body dementia but with the right treatment early on, it is possible to delay the worsening of someone’s symptoms. 

Most people with Lewy body dementia need a comprehensive combination of treatment, including medications, counseling, and physical therapies. It is important to work with clinicians to manage your treatments and the way they interact with each other and your symptoms. It might also be necessary to make changes to your home to make it safer and buy certain items that make your daily routine easier.

As with diagnosing Lewy body dementia, ongoing treatment involves a range of medical professionals. Within your care team, there should be one doctor who coordinates with other clinicians and is the main point of contact for you and your family. You will also work with a neurologist who is a specialist in dementia and, depending on your symptoms, a range of occupational therapists like a speech or movement therapist, mental health practitioners, and end of life specialists, based on your age and how far your condition has progressed.


Some people with Lewy body dementia are prescribed antipsychotic medication for symptoms like hallucinations; however, these are powerful medicines and can prompt strong side effects like worsening someone’s movement symptoms, impacting their blood pressure levels, extreme fatigue, and even increased risk of death. 

Doctors are often hesitant to prescribe this medication to older people because of these risks but if you are taking antipsychotics, it is important to stay in regular contact with your doctor to monitor these side effects. [9]

Other medications that are sometimes prescribed are cholinesterase inhibitors, which help with the cognitive symptoms of Lewy body dementia and its impact on memory. These can also help with delusions and hallucinations. Another drug commonly prescribed for people with Alzheimer’s, rivastigmine, can be given to people with Lewy body dementia or Parkinson’s disease dementia, to treat cognitive symptoms.

Similarly, there is some crossover in the medication prescribed for Parkinson’s disease and Lewy body dementia, like carbidopa-levodopa, which can help with movement-related symptoms but can trigger side effects like hallucinations.

Other medications that are sometimes prescribed include clonazepam, which can help with seizures and panic attacks and melatonin for insomnia or sleep disruption, although this can also cause side effects like dizziness.

If you are struggling with sleepiness, your doctor might give you stimulants, and there are other lower strength medications that can be used for mood swings and behavioral problems once environmental triggers have been ruled out or mitigated. A doctor might give you antidepressants if you are experiencing anxiety or depression as part of your Lewy body dementia.

Altogether, the combination of the medications you take and how they interact with each other is often complex for people with Lewy body dementia and requires close support from clinicians.

Self-care for Lewy body dementia

Self-care is a really important part of living well with Lewy body dementia. Some people find that joining a group with other people with Lewy body dementia, and their friends and family, can help them to feel less alone while managing their condition. If you don’t want to join a group, try to find one or two people you trust with whom you can talk about your symptoms and feelings.

You can also take part in activities that help to slow down the development of your symptoms. There is some evidence that shows that playing memory games can help with cognitive symptoms and that physical therapy and exercise help with movement symptoms like muscle rigidity. Research also shows that art and music therapy can help with memory and mental health symptoms.

If you struggle with sleep, try to avoid taking naps during the day or stimulants like coffee too late in the day, as this can aggravate your symptoms.

Because of the impact of Lewy body dementia on the nervous system and the body’s ability to autoregulate, it can help to keep your legs elevated or to wear flight compression socks to help with blood flow around the body. 

Your doctor might also recommend changes to your diet, like increasing the amount of water you drink in a day or taking vitamins or supplements to boost the levels of salt or iron in your body. [10]

Helping someone with Lewy body dementia

The role of family and friends in supporting someone with Lewy body dementia cannot be overstated. Because of some of the symptoms associated with this condition, some people will not notice that they are feeling or acting differently. 

It is important for the people around them to monitor them and seek medical advice as early as possible if they think they might be developing Lewy body dementia. If you are concerned about a person’s reaction at your suggestion of going to the doctor with them, you can ask to speak to a doctor privately on their behalf first.

Family and friends also play a key role in helping someone with this condition to follow their treatment plan and monitor side effects of any medication they are taking. They can also support in making the person’s home as safe and comfortable as possible. 

Because Lewy body dementia is a complex condition, it can help to read up on it and even go on a course to understand how best to support your loved one. With the right skills, friends’ and families’ presence in someone’s home can help to improve their mood and any mental health symptoms.

Ultimately, looking after someone with Lewy body dementia takes a lot of time, patience, and energy. For many people, there comes a point where they require professional care or to seek supportive accommodations. If the person you are helping has started resisting care or reacting strongly to you physically or verbally, it is important to seek professional help.

Remember to also look after yourself – you cannot support someone with Lewy body dementia if you don’t give yourself enough rest outside of the times you are with them. Where possible, try to find activities that help you to relax. You might also want to join a support group for friends and family of people with Lewy body dementia. [11] 

FAQs about Lewy body dementia

How common is Lewy body dementia?

Lewy body dementia is relatively uncommon, with approximately one million people in the US diagnosed with this condition. [12]

It is most common in older people, particularly those over 60, and is the second most common type of progressive dementia after Alzheimer’s disease.

What is the difference between Alzheimer’s disease and Lewy body dementia?

While there is a lot of crossover in the symptoms of these two diagnoses, there are some subtle differences. Look out for changes in your attention span and ability to concentrate, as well as unusual periods of feeling awake, as these tend to be signs of Lewy body dementia (and are less common with Alzheimer’s).

People with Alzheimer’s disease also experience memory loss as one of their first symptoms and it can come on very quickly, whereas it tends to come on slowly for people with Lewy body dementia.

What is the outlook for people with Lewy body dementia?

While there is no cure for Lewy body dementia, with the right treatment and support from family and friends, it is possible to manage your symptoms well and delay them worsening. It is important to remember that there is no definitive research that shows that there are lifestyle changes you can make to avoid developing Lewy body dementia. [13]

Lewy body dementia is by nature a progressive disease, so someone’s symptoms will gradually worsen, on average over five to eight years. Sadly, people with dementia can die from it, most commonly because of falls, the side effects of strong medication, suicide as a result of mental health symptoms, problems with swallowing food and drink, and issues with mobility.

The average life expectancy for somebody with Lewy body dementia is five to eight years after the initial diagnosis, but some people with this condition live for up to 20 years after receiving a diagnosis. [14]

  1. Genetic and Rare Diseases Information Center.Lewy body d Retrieved November 2022, from https://rarediseases.info.nih.gov/diseases/3243/lewy-body-dementia 
  2. Haider, A., Spurling, B.C., Sánchez-Manso, J.C. (2022). Lewy body dIn StatPearls. StatPearls Publishing. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK482441/ 
  3. National Institute on AgWhat is Lewy body dementia? Causes, symptoms, and treatments. Retrieved November 2022, from https://www.nia.nih.gov/health/what-lewy-body-dementia-causes-symptoms-and-treatments 
  4. Gomperts, S.N. (2016). Lewy body dementias: Dementia with Lewy bodies and Parkinson disease d The American Academy of Neurology.Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5390937/ 
  5. National Institute on AgWhat is Lewy body dementia? Causes, symptoms, and treatments. Retrieved November 2022, from https://www.nia.nih.gov/health/what-lewy-body-dementia-causes-symptoms-and-treatments 
  6. Mouton, A., Blanc, F., Gros, A., Manera, V., Fabre, R., Sauleau, E., et al. (2018).Sex ratio in dementia with Lewy bodies balanced between Alzheimer’s disease and Parkinson’s disease dementia: A cross-sectional study. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6136211/ 
  7. Chia, R., Sabir, M.S., Bandres-Ciga, S., Saez-Atienzar, S., Reynolds, R.H., et al. (2021). Genome sequencing analysis identifies new loci associated with Lewy body dementia and provides insights into its genetic architecture. Retrieved fromhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC7946812/ 
  8. Huang, J. (2022).Dementia with Lewy bodies and Parkinson disease d Retrieved from https://www.merckmanuals.com/professional/neurologic-disorders/delirium-and-dementia/dementia-with-lewy-bodies-and-parkinson-disease-dementia?query=lewy%20body%20dementia 
  9. McKeith, I.G., Dickson, D.W., Lowe, J., Emre, M., O’Brien, J.T.,  Feldman, H., et al. (2005).Diagnosis and management of dementia with Lewy bodies. Retrieved from https://n.neurology.org/content/65/12/1863.short 
  10. Connors, M.H., Quinto, L., McKeith, I., Brodaty, H., Allan, L., et al. (2018). Non-pharmacological interventions for Lewy body dementia: Asystematic review.
    Retrieved from https://ncbi.nlm.nih.gov/pmc/articles/PMC6088773/ 
  11. Caring for a person with Lewy body dementia. (2018). Retrieved November 2022, from http://www.nia.nih.gov/health/caring-person-lewy-body-dementia 
  12. National Institute on AgWhat is Lewy body dementia? Causes, symptoms, and treatments. Retrieved November 2022, from https://www.nia.nih.gov/health/what-lewy-body-dementia-causes-symptoms-and-treatments 
  13. Lewy body dementia: Hope through research. National Institute of Neurological Disorders and Stroke. US National Institutes of Health. (2015).Retrieved from https://www.ninds.nih.gov/health-information/patient-caregiver-education/hope-through-research/lewy-body-dementia-hope-through-research
  14. Haider, A., Spurling, B.C., Sánchez-Manso, J.C. (2022). Lewy body dementia. In StatPearls. StatPearls Publishing. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK482441/
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Cristina Po Wenger
Author Cristina Po Wenger Writer

Cristina Po Wenger is a medical writer and mental health advocate with a Sociology Degree from the University of Stirling.

Published: Dec 21st 2022, Last edited: Oct 23rd 2023

Amy Shelby
Medical Reviewer Amy Shelby M.S. Counseling Psychology

Amy Shelby is a medical reviewer with a B.A. in Psychology from Northwestern and an M.S. in Psychology from Chatham University.

Content reviewed by a medical professional. Last reviewed: Dec 21st 2022