Hallucinations vs. Delusions: A Caregiver’s Guide to Seeing Clearly

When your loved one sees someone who isn’t there or insists you’ve stolen their wallet, it’s easy to feel confused and hurt. These are two different symptoms: hallucinations are sensory experiences (seeing, hearing, feeling things that aren’t real), while delusions are false beliefs held despite all evidence. Both are caused by brain changes from dementia, not by stubbornness or spite. The good news is there are concrete, compassionate ways to respond that can reduce distress for both of you. This guide will help you tell them apart and give you step-by-step actions to try today.

Key points

Hallucinations are sensory false perceptions (seeing, hearing, feeling things not there); delusions are false beliefs held despite evidence.
Never argue or try to prove them wrong—it increases distress and makes symptoms worse.
Always validate the feeling behind the symptom (fear, worry) and then redirect to a calming activity.
Check for environmental triggers like shadows, reflections, or clutter that can spark hallucinations.
Rule out medical causes like infections or medication side effects before assuming it’s dementia-related.
Document episodes and share with the doctor—it helps guide treatment and identify patterns.

What Is a Hallucination?

A hallucination is when the brain tricks itself into thinking something is there when it is not. It is a false sensory perception—the person actually sees, hears, smells, tastes, or feels something that has no external source. For example, they might see a person standing in the corner, hear voices talking, feel insects crawling on their skin, smell smoke, or taste metal. These experiences are very real to them because their damaged brain is creating the sensation. Hallucinations can affect any of the five senses, but visual hallucinations are the most common in dementia, especially in Lewy body dementia where they often appear early and involve seeing small animals, children, or unfamiliar people.

What Is a Delusion?

A delusion is a false belief that a person holds onto tightly, even when presented with clear evidence that it isn’t true. It is a thinking problem, not a sensory one. Common delusions in dementia include believing someone is stealing from them, that their spouse is cheating, that they have been abandoned, or that they need to go to work even though they retired years ago. Delusions often stem from the brain’s attempt to make sense of confusing situations—like misplacing a wallet and then concluding it must have been stolen. Unlike hallucinations, delusions are about interpreting the world around them incorrectly, not about sensing things that aren’t there.

Why Do These Happen in Dementia?

Both hallucinations and delusions are caused by physical damage to the brain from diseases like Alzheimer’s, Lewy body dementia, or other dementias. In Alzheimer’s, hallucinations may appear in middle to late stages, while in Lewy body dementia they are a hallmark early symptom—about 80% of people with Lewy body dementia experience hallucinations, often as one of the first warning signs. Delusions are also common across dementia types and can be triggered by memory loss, confusion, or changes in the brain’s ability to process information. The key is to remember that these are symptoms of the disease, not intentional behaviors. Your loved one is not trying to upset you; their brain is misfiring.

General caregiving information, not medical advice. Check medications and major care changes with your clinician.

Step-by-step

During a hallucination, calmly acknowledge what the person sees without agreeing it's real: 'I see you're looking at something. Tell me about it.'
During a delusion, avoid arguing or proving the belief wrong; instead validate the feeling: 'It must feel upsetting to think someone took your wallet. Let's look together.'
Assess for possible causes: check for pain, hunger, thirst, need to use the bathroom, medication side effects, or sensory deficits (e.g., poor vision or hearing).
Redirect to a safe, reassuring activity or environment—change the room, offer a familiar object, or engage in a soothing task like folding laundry or looking at photos.
If the symptom is new or escalates, consult a doctor to rule out infection, metabolic changes, or medication issues, and discuss non-pharmacological or low-dose medication options.

What not to do

Do not argue, correct, or try to prove the hallucination or delusion is false—this increases distress and agitation.
Do not scare or shame the person; avoid saying 'that's not real' or 'you're being paranoid.'
Do not ignore or dismiss the symptom as deliberate misbehavior—it results from brain disease.
Do not use physical or chemical restraints as a first response; prioritize environmental and behavioral approaches.

Practical tools

Reality-validation phrases
Prepare short, neutral statements like 'I can see you're concerned about that' or 'Let me help you with this,' to acknowledge distress without reinforcing false content.
Safety-proofed environment
Remove tripping hazards, secure clutter, and ensure good lighting to reduce misinterpretation of shadows or reflections that can trigger hallucinations.
Medical review checklist
Have a simple list for doctor visits: note onset, frequency, content of the symptom, recent medication changes, and any signs of infection (fever, UTI symptoms).

What should I do if my loved one suddenly starts hallucinating or having delusions?

First, stay calm and check for sudden physical causes like a urinary tract infection, dehydration, or medication changes—these are common triggers. Validate their fear by saying 'That sounds scary, I'm here with you,' then gently redirect to a calming activity like folding towels or looking out the window.

What physical problems can cause new or worsening hallucinations and delusions?

New or worsening symptoms are often caused by infections (especially UTIs), dehydration, medication side effects, pain, constipation, or poor eyesight and hearing. Rule these out by checking for fever, discomfort, or changes in routine, and call the doctor promptly if you suspect a physical issue.

Why does my loved one with dementia vividly remember delusions but not real events?

Due to brain changes from dementia, emotional memories (like fear or mistrust) are stored more strongly than factual ones, while recent events fade quickly. Instead of correcting them, focus on soothing the feeling—say 'I can see you're upset, let's sit together'—and redirect to a safe, soothing task.

Discuss with your clinician

If hallucinations or delusions appear suddenly or worsen quickly, especially with confusion or fever—this could be delirium from an infection like a UTI.

If the person becomes aggressive or tries to harm themselves or others because of a hallucination or delusion.

If non-drug approaches have been tried for several weeks without improvement and the symptoms are very distressing.

Before starting any medication for hallucinations or delusions—ask about side effects, especially for Lewy body dementia where some antipsychotics can be dangerous.

If you notice new physical symptoms like trouble walking, tremors, or sleep changes along with hallucinations—this could indicate Lewy body dementia or another condition.