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How to Tell the Difference Between Hallucinations and Illusions in People with Dementia

Hallucinations refer to sights, sounds, and smells that come from inside the brain. Hallucinations are common with Lewy Body Dementia but can happen with any dementia. The person with dementia is seeing, hearing, or smelling stuff that the rest of us are not experiencing. Illusions refer to mis-seeing (misperceiving) objects that ARE real. So how do you figure out the difference? And does it matter? Yes! Read on…

“Normal” Illusions

Take a look at the picture with this blog. Do you see 2 cats in front of a moon, or one dog? Look again, and you will notice you can “flip” between images. Our brains have the ability to see, or perceive, multiple aspects of one picture. This is normal, and you can have fun with it.

Illusions and Dementia

People with dementia may experience “breakdowns” in the highways that connect different parts of the brain. The connections in the brain help us to identify what we see. When I see a furry animal with whiskers, 4 paws, and a tail, my brain tells me that I am seeing a cat. But when the highways slow down or break down completely, I may look at something and my brain connects what I am seeing to something else. For example, I was caring for a relative with dementia who lived with me. She was convinced that the white throw pillows on my black couch were dogs. Sleeping dogs. I suggested that she come over to the couch and see that the objects were pillows. Nope. She was afraid of dogs. So I took the pillows to her. We laughed. She also had some eye problems and wore glasses, so part of the issue may have been distortion due to physical reasons (and smudged glasses).

Illusions or Hallucinations?

A couple of weeks ago, I was on call and fielded a phone call from a caregiver who was upset because of her dad’s hallucinations. “He keeps seeing men in the house. He won’t settle down, he keeps looking for the men and he wants me to call the police.” I asked her a couple of questions and found out that the “men” appeared after dark and in specific rooms.

“Do these rooms have windows?” I asked.


“Do the windows have curtains?” I was sure she thought I was goofy, but she was patient with me.

“Yes, but just along the top half. The bottom halves are uncovered. We live in a wooded area with complete privacy, so we don’t have to worry about people looking in.”

I instructed the daughter to walk through the rooms and see if she could see her reflection in the darkened windows while the rooms were brightly lit.

“YES!” she excitedly answered.

Turns out, dad was NOT having hallucinations. He was seeing his distorted image in the uncovered windows, which became funhouse mirrors once it got dark outside. His daughter promptly had shutters installed. Problem solved.

How To Handle Hallucinations

Do the Hallucinations Bother the Person with Dementia?

Towards the end of Mary’s time with me, she began to sit in her chair and pick at the air. I watched her one day, and asked what she was doing.

“I’m pulling the yarn down from the ceiling,” she calmly replied. She was seeing shiny strands of brightly colored yarn and was delightedly harvesting them. Apparently, she was going to use them in a future arts and crafts project. Her son was freaked out by her hallucinations and demanded I “call someone” to get her medication. I refused. The hallucinations were not bothering her, so they were not bothering me.

Creative Problem-Solving

Another family caregiver shared his story with me. His wife (who had dementia) would stand at the kitchen window every day to look at the birds. This was something she enjoyed. One day, she became upset  and told him that a man was sitting in the tree looking in the house. The husband gazed out the window but all he saw was a lone branch jutting off the trunk of the tree. He replied, “Honey, I don’t see anything.” He  suggested that they move away from the window and go do something else in another part of the house. This went on for about a week, with his wife becoming increasingly upset. He simply cut down the tree branch. The hallucinations stopped. Maybe his wife did have visual hallucinations. Maybe his wife was looking at the leaves around the tree branch and was seeing an illusion of a person.

Are Medications Appropriate?

If the hallucinations are scary and upsetting, I will prescribe something. Usually an atypical antipsychotic, and yes, I know these medications get bad reps because they are being used off-label. However, if the medication reduces the scary and upsetting hallucination, and the person with dementia is no longer scared and upset, I think the use of the medication is appropriate. This is my humble opinion, others are free to disagree with me.

The Bottom Line

I always ask questions when I’m told about possible hallucinations. Illusions can be easy to fix, especially with a little creativity. Good lighting and removing clutter are two ways to reduce the incidence of visual illusions.


Are you a caregiver or care partner for someone with dementia? Would you like to learn more about behaviors and how to prevent and manage them? Click here for information on upcoming webinars and other options!

Categories: Alzheimer's Disease Care Partners Caregiving Dementia FTD Lewy Body Dementia Understanding Behaviors

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Dr. Rita Jablonski

Rita Jablonski, PhD, CRNP, FAAN, FGSA is a nurse practitioner, researcher, tenured professor, and former family caregiver. Her research and practice involve all aspects of dementia management; she is best known for non-drug strategies to address dementia-related behaviors.

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