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Nobody expects to become an expert on Lewy body dementia (LBD). Yet here you are, searching for answers because something feels off with someone you love. Maybe it’s been a slow realization over months, or perhaps a sudden change sent you looking for answers. Either way, you’re worried.

The changes you’re seeing don’t match what you know about normal aging or even typical dementia. Your loved ones may see things that aren’t there, but seems perfectly rational otherwise. They move differently than they used to, shuffling when they walk. The doctor mentioned Parkinson’s, but wasn’t sure.. Another doctor suggested depression. Nothing quite fits.

What you’re seeing could be early signs of Lewy body dementia. This condition often goes unrecognized for years because its symptoms look a lot like other conditions. People get diagnosed with Parkinson’s disease, Alzheimer’s disease, depression, or sleep disorders when they actually have LBD.

Understanding the early warning signs can help you get the right diagnosis sooner. This is important because certain medications commonly used for other conditions, particularly antipsychotic drugs, can be dangerous for people with Lewy body dementia.

What Are the First Signs of Lewy Body Dementia?

Keep in mind that these symptoms won’t all appear in every person with LBD, and they may show up at different times or in different combinations

1. Visual Hallucinations

Visual hallucinations are one of the first and most distinctive signs of Lewy body dementia. The hallucinations are detailed and formed visions that seem completely real in the moment.

The hallucinations often follow patterns. Many people see children or young adults in their home. Others see animals, particularly cats or dogs. Some see patterns on walls or curtains that appear to move or change. The visions usually happen when the person is awake and alert, not when they’re drowsy or just waking up.

What makes these hallucinations different from other conditions is that people with LBD sometimes know the visions aren’t real, at least early on. They might say, “I know there’s no one there, but I see them anyway.” This insight can fade as the disease progresses, but in the beginning, there’s usually awareness that these are hallucinations.

These visions are not a sign of psychiatric illness, and they’re not caused by medications in most cases. They’re a direct result of how Lewy body dementia affects the brain’s visual processing areas. When a doctor hears about visual hallucinations in someone who also has cognitive or movement problems, it should immediately raise the possibility of LBD.

2. Acting Out Dreams During Sleep

People with LBD often act out their dreams in ways that can be violent or dangerous. This is called REM sleep behavior disorder, and it frequently appears years before any other symptoms.

During normal REM sleep, your muscles are temporarily paralyzed, so you can’t act out your dreams. In REM sleep behavior disorder, this protective mechanism doesn’t work. You might wake up to find your partner punching the air, yelling at someone who isn’t there, or thrashing around during what seems like a violent dream. Some people fall out of bed or injure themselves or their partner.

These episodes happen during deep sleep, typically in the second half of the night when REM sleep is most common. The person is completely asleep and usually doesn’t remember the episodes the next morning. They might recall having vivid or violent dreams but not realize they were actually moving or shouting.

What makes this symptom particularly important is that it can appear 10 to 15 years before other signs of Lewy body dementia. If your loved one has been acting out dreams for years and now has other symptoms on this list, that history of sleep problems becomes an important diagnostic clue.

3. Unpredictable Changes in Alertness and Thinking

One of the most confusing aspects of Lewy body dementia is how much a person’s alertness and thinking can change throughout the day. They might be clear, coherent, and capable in the morning, then confused and drowsy by afternoon. An hour later, they might be alert again.

These fluctuations can be dramatic. During a clear period, the person can hold complex conversations, remember recent events, and function normally. During a confused period, they might not recognize where they are, struggle to complete simple sentences, or stare into space for long stretches.

The cognitive changes don’t follow the steady, predictable decline of Alzheimer’s disease. Instead, thinking problems fluctuate along with alertness. Attention and concentration are often affected more than memory, at least early on. The person might lose track of conversations mid-sentence, find it difficult to find the correct words, struggle to focus on tasks, or seem to drift in and out of awareness. They might start a task and forget what they were doing, not because they can’t remember the goal but because they can’t maintain focus.

The changes don’t follow a predictable pattern. Some days are better than others. Some hours are better than others. You can’t reliably plan activities around these fluctuations because they’re so variable. This unpredictability is exhausting for families and confusing for doctors who might only see the person during a good period.

These fluctuations are different from the sundowning seen in Alzheimer’s disease, which tends to follow a more predictable late-afternoon pattern. In LBD, the changes can happen at any time and can shift multiple times throughout a single day. This variability itself is a diagnostic clue. If cognitive and alertness problems seem to come and go rather than steadily worsen, LBD should be considered.

4. Movement Changes Similar to Parkinson’s Disease

Lewy body dementia causes movement problems that are similar to Parkinson’s disease. Movement becomes slower than usual, with simple tasks like getting up from a chair or walking across a room taking longer. Steps become shorter and shuffled. One arm swings less when the person walks.

Stiffness often appears, particularly in the arms and legs. Simple tasks like buttoning a shirt or using utensils become harder. Facial expressions become less animated, giving the person a flat or mask-like appearance.

A tremor can develop, though it’s less common in LBD than in Parkinson’s disease. When tremor does occur, it’s usually a resting tremor, meaning it happens when the limb is relaxed rather than during movement.

The timing of these symptoms is the key difference from Parkinson’s disease. In Parkinson’s, movement problems usually appear years before any cognitive changes. In Lewy body dementia, movement problems develop around the same time as cognitive symptoms or shortly after. If someone has both movement and thinking problems appearing together, LBD is more likely than Parkinson’s.

5. Problems with Spatial Awareness and Visual Processing

People with Lewy body dementia often struggle with tasks that require visual-spatial skills, even when their basic vision is normal. They misjudge distances, bump into doorframes, and have trouble navigating familiar spaces. Pouring liquids or reaching for objects accurately becomes difficult because their depth perception is affected.

Getting lost in familiar places becomes a common occurrence. Your loved one may get confused in their own neighborhood or have trouble finding rooms in their own home.

Reading can become difficult as their brain struggles to organize the letters and words on a page. Someone who used to read for hours might lose their place after a few sentences or struggle to follow lines of text across the page.

These spatial problems can also make activities such as driving, going up or down the stairs and even walking through a crowded room really dangerous.

6. Severe Sensitivity to Antipsychotic Medications

People with Lewy body dementia can have severe, dangerous reactions to antipsychotic medications that are routinely prescribed for agitation, confusion, or hallucinations in other types of dementia.

These reactions can be life-threatening. Standard antipsychotics can cause sudden worsening of movement symptoms, extreme sedation, high fever, or a condition called neuroleptic malignant syndrome that can be fatal. Even newer antipsychotics marketed as safer can cause serious problems in people with LBD.

If someone has ever had a bad reaction to medications like haloperidol (haldol) or risperidone, that reaction itself is a red flag for possible Lewy body dementia. Many people with LBD get their diagnosis only after they have a severe reaction to one of these medications, particularly in an Emergency Room setting when a drug may be given for agitation.

This is why getting the right diagnosis matters so much.

7. Depression, Anxiety, or Apathy That Doesn’t Respond to Treatment

Mood changes often appear early in Lewy body dementia, sometimes years before other symptoms become obvious. Depression can develop, with the person losing interest in activities they used to enjoy. Anxiety often emerges, showing up as excessive worrying about minor things or fear in situations that never bothered them before.

Apathy is particularly common. The person seems emotionally flat and shows little interest in anything. They stop initiating activities, stop making plans, and seem indifferent to things they used to care about. This looks like depression, but standard antidepressant treatments often don’t help much.

What makes these mood symptoms different is that they appear alongside other symptoms on this list. If your loved one has depression and also has movement problems, sleep issues, or hallucinations, the combination suggests LBD rather than primary depression.

These mood symptoms aren’t just reactions to having a disease. They’re part of how Lewy body dementia affects brain chemistry and function. Recognizing them as part of LBD rather than separate conditions helps doctors choose safer, more effective treatments.

8. Problems with Blood Pressure and Body Temperature Regulation

Blood pressure problems are common in Lewy body dementia. The person feels dizzy or lightheaded when standing up because their blood pressure drops suddenly. Fainting or near-fainting episodes occur, especially after sitting or lying down for a while. These episodes happen because the autonomic nervous system, which normally adjusts blood pressure automatically, isn’t working properly.

Body temperature regulation can be affected too. The person may sweat excessively or not sweat enough. They may feel too hot or too cold even when the room temperature seems comfortable to everyone else.

Other autonomic problems include constipation, urinary difficulties, and sexual dysfunction. These symptoms often appear early and can be severe. If your loved one has several of these autonomic problems along with cognitive or movement symptoms, LBD becomes more likely.

Doctors often treat these symptoms individually without recognizing they’re part of a larger pattern. When you see multiple autonomic problems appearing together with other LBD symptoms, the combination is significant.

9. A Sense That Something Is Wrong Before Anyone Else Notices

This isn’t a medical symptom, but it’s often the first sign families recognize in retrospect. You might have felt for months or even years that something was off, even when you couldn’t put your finger on what was wrong. Small things seemed different. Your loved one wasn’t quite themselves.  That early sense of something being off is real. It reflects your awareness of subtle changes that add up over time.

Maybe they seemed less engaged in conversations. Maybe they moved a bit differently. Maybe they had odd moments of confusion that passed quickly. These subtle changes were easy to dismiss as stress, aging, or temporary problems.

Trust your instincts. You know your loved one better than any doctor who sees them in an office visit. If you feel something is wrong, even when you can’t clearly articulate what it is, that feeling deserves attention. Keep track of what you’re noticing. Write down specific examples. These observations can help doctors see patterns that aren’t obvious during a brief office visit.

What to Do If You Recognize These Signs

If several of these symptoms sound familiar, the next step is getting a proper evaluation. Write down what you’re seeing, when symptoms started, how often they happen, and any patterns you’ve noticed, and include even the smallest details.  Bring these notes to medical appointments.

See a specialist. Movement disorder neurologists and behavioral neurologists have more experience recognizing Lewy body dementia than general practitioners. They know what patterns to look for and which tests might help. When you describe symptoms, be specific. Don’t just say “memory problems” or “confusion.” Describe the fluctuations in alertness, the visual hallucinations, the movement changes. Mention any past reactions to medications, especially antipsychotics or anti-nausea drugs, as these reactions are important diagnostic clues.

Getting the right diagnosis takes time, but recognizing these early warning signs can help speed up the process. The sooner you identify Lewy body dementia, the sooner you can access appropriate treatments and avoid medications that could make things worse.

If you need help finding specialists who understand Lewy body dementia or have questions about what you’re seeing, we’re here to help. Our team is available every day of the year from 8am to 8pm Eastern time at 516-218-2026 or 833-LBDLINE. You can also reach us at norma@lbdny.org.