Lewy Body Dementia
Learn about Lewy Body Dementia, its reported features, relevant specialists, and questions to discuss at a medical consultation.
Also known as: Dementia with Lewy Bodies; LBD; Lewy body disease; Parkinson's disease dementia
The sources compiled here do not cover: prevention, onset, prevalence. Ask the treating doctor about these.
What is Lewy body dementia (LBD)?
From: MedlinePlus, National Library of Medicine
Lewy body dementia (LBD) is one of the most common types of dementia in older adults. Dementia is a loss of mental functions that is severe enough to affect your daily life and activities. These functions include:
- Memory
- Language skills
- Visual perception (your ability to make sense of what you see)
- Problem solving
- Trouble with everyday tasks
- The ability to focus and pay attention
What are the types of Lewy body dementia (LBD)?
From: MedlinePlus, National Library of Medicine
There are two types of LBD: dementia with Lewy bodies and Parkinson's disease dementia.
Both types cause the same changes in the brain. And, over time, they can cause similar symptoms. The main difference is in when the cognitive (thinking) and movement symptoms start.
Dementia with Lewy bodies causes problems with thinking ability that seem similar to Alzheimer's disease. Later, it also causes other symptoms, such as movement symptoms, visual hallucinations, and certain sleep disorders. It also causes more trouble with mental activities than with memory.
Parkinson's disease dementia starts as a movement disorder. It first causes the symptoms of Parkinson's disease: slowed movement, muscle stiffness, tremor, and a shuffling walk. Later on, it causes dementia.
What causes Lewy body dementia (LBD)?
From: MedlinePlus, National Library of Medicine
LBD happens when Lewy bodies build up in parts of the brain that control memory, thinking, and movement. Lewy bodies are abnormal deposits of a protein called alpha-synuclein. Researchers don't know exactly why these deposits form. But they do know that other diseases, such as Parkinson's disease, also involve a build-up of that protein.
Who is at risk for Lewy body dementia (LBD)?
From: MedlinePlus, National Library of Medicine
The biggest risk factor for LBD is age; most people who get it are over age 50. People who have a family history of LBD are also at higher risk.
What are the symptoms of Lewy body dementia (LBD)?
From: MedlinePlus, National Library of Medicine
LBD is a progressive disease. This means that the symptoms start slowly and get worse over time. The most common symptoms include changes in cognition, movement, sleep, and behavior:
- Dementia, which is a loss of mental functions that is severe enough to affect your daily life and activities
- Changes in concentration, attention, alertness, and wakefulness. These changes usually happen from day to day. But sometimes they can also happen throughout the same day.
- Visual hallucinations, which means seeing things that are not there
- Problems with movement and posture, including slowness of movement, difficulty walking, and muscle stiffness. These are called parkinsonian motor symptoms.
- REM sleep behavior disorder, a condition in which a person seems to act out dreams. It may include vivid dreaming, talking in one's sleep, violent movements, or falling out of bed. This may be the earliest symptom of LBD in some people. It can appear several years before any other LBD symptoms.
- Changes in behavior and mood, such as depression, anxiety, and apathy (a lack of interest in normal daily activities or events)
In the early stages of LBD, symptoms can be mild, and people can function fairly normally. As the disease gets worse, people with LBD need more help due to problems with thinking and movement. In the later stages of the disease, they often cannot care for themselves.
How is Lewy body dementia (LBD) diagnosed?
From: MedlinePlus, National Library of Medicine
There isn't one test that can diagnose LBD. It is important to see an experienced doctor to get a diagnosis. This would usually be a specialist such as a neurologist. The doctor will:
LBD can be hard to diagnose, because Parkinson's disease and Alzheimer's disease cause similar symptoms. Scientists think that Lewy body disease might be related to these diseases, or that they sometimes happen together.
It's also important to know which type of LBD a person has, so the doctor can treat that type's particular symptoms. It also helps the doctor understand how the disease will affect the person over time. The doctor makes a diagnosis based on when certain symptoms start:
- Do a medical history, including taking a detailed account of the symptoms. The doctor will talk to both the patient and caregivers.
- Do physical and neurological exams
- Do tests to rule out other conditions that could cause similar symptoms. These could include blood tests and brain imaging tests.
- Do neuropsychological tests to evaluate memory and other cognitive functions
- If cognitive symptoms start within a year of movement problems, the diagnosis is dementia with Lewy bodies
- If cognitive problems start more than a year after the movement problems, the diagnosis is Parkinson's disease dementia
What are the treatments for Lewy body dementia (LBD)?
From: MedlinePlus, National Library of Medicine
There is no cure for LBD, but treatments can help with the symptoms:
- Medicines may help with some of the cognitive, movement, and psychiatric symptoms
- Physical therapy can help with movement problems
- Occupational therapy may help find ways to more easily do everyday activities
- Speech therapy may help with swallowing difficulties and trouble speaking loudly and clearly
- Mental health counseling can help people with LBD and their families learn how to manage difficult emotions and behaviors. It can also help them plan for the future.
- Music or art therapy may reduce anxiety and improve well-being
Support groups can also be helpful for people with LBD and their caregivers. Support groups can give emotional and social support. They are also a place where people can share tips about how to deal with day-to-day challenges.
Which doctor should you see?
The suggested department for discussing Lewy Body Dementia is Neurology, with a neurologist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.
This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.
How to prepare for an assessment
Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.
Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.
- Which nervous-system findings help explain the symptoms?
- Would an assessment of walking, communication or daily function be helpful?
- Are rehabilitation or other specialist services relevant?
Treatment discussions and follow-up
Where the source describes treatments, these are an overview of possible care, not a prescription for an individual. Ask which option applies to the confirmed diagnosis, what benefit is expected, what adverse effects to watch for and how progress will be assessed. Availability, approvals and local practice can differ from the country described in the source.
Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.
The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.
When to seek emergency help
Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.
This condition is usually assessed by a neurologist. Every profile shows the doctor’s registration and what has been checked.
Sources
- MedlinePlus, National Library of Medicine — Lewy Body Dementia — Public-domain health-topic summary
- Government of India — Emergency Response Support System — Official reference for India emergency number
Source: MedlinePlus, National Library of Medicine. Orphadata Science: Free access data from Orphanet. © INSERM 1999; July 2026 data, CC BY 4.0. This product uses the Human Phenotype Ontology (hp/releases/2026-09-01). Only sources listed for this article apply. Source material has been selected and arranged; HPO definitions are reproduced without alteration. No source organisation endorses this compilation. Köhler S et al. The Human Phenotype Ontology project: linking molecular biology and disease through phenotype data. Nucleic Acids Research 2014;42(D1):D966–D974. doi:10.1093/nar/gkt1026.
General information, not advice about your situation. Errors can be reported through the corrections process. Reference TDI-C-1420.