People with Parkinson’s disease sometimes see, hear, smell, or feel things that aren’t real. Someone might see a dead relative in the room or feel the sensation of bugs crawling on their skin when nothing is there.

These sensory changes are called hallucinations, and visual hallucinations are the most common type of hallucination in Parkinson’s disease.

Hallucinations are the most common symptom of Parkinson’s psychosis, a condition that occurs as a side effect of the medications used to treat Parkinson’s disease. Delusions, which are false beliefs, aren’t common in Parkinson’s disease.

Between 20 and 40 percent of people with Parkinson’s disease will hallucinate at some point in their disease. The longer people live with Parkinson’s, the more likely they are to have these unreal experiences.

The medications people take to manage Parkinson’s symptoms play a big role in triggering psychosis. Every drug used to treat this disease causes hallucinations as a side effect. This symptom usually improves once you lower the dosage or stop taking the medication.

These medications alter dopamine levels. Dopamine is a brain chemical that helps the body move smoothly and the brain control emotions.

Although defective dopamine metabolism in the brain from the disease can cause hallucinations, medications are the primary cause. It’s very rare for people with Parkinson’s disease to have this symptom if they aren’t undergoing dopaminergic treatment.

Hallucinations can be troubling to the person having them and anyone who’s around them at the time. That’s why it’s important to be prepared and know what to do when they happen.

You can tell that your loved one is having a hallucination if they talk about seeing, hearing, smelling, feeling, or tasting something that isn’t real. Examples include:

  • seeing something that isn’t there, like a dead family member in the room
  • sensing a person’s presence when no one is around
  • hearing sounds, like a violin playing or a dog barking, that no one else can hear
  • feeling something that isn’t real, like raindrops on their skin when there’s no rain
  • thinking that one thing is another — for example, that a pile of laundry is the family dog
  • tasting something that’s not related to anything they’ve eaten

Seeing things as different from they really are (a dog instead of a pile of laundry) may have to do with changes in not only the brain but also the eye.

People with Parkinson’s have thinning in their retina, the part of the eye that transmits images to the brain for processing. This thinning may cause a glitch in the way the brain interprets images.

In the early stages of the disease, your loved one might realize that what they’re experiencing isn’t actually happening.

This is called having insight. Since most doctors will mention the possibility of hallucinations as a medication side effect, it doesn’t usually come as a shock to someone who’s experiencing them.

As the disease progresses, they may develop Parkinson’s disease associated dementia or another type of dementia, like Alzheimer’s disease. With dementia, they can lose insight and believe their hallucinations are real.

Usually, the lack of insight is due to dementia, rather than Parkinson’s itself. Dementia is a loss of reasoning and thinking ability that’s not uncommon in people with late stage Parkinson’s disease.

Most importantly, don’t try to convince your loved one that what they’re experiencing isn’t real. They’ll feel like you’re putting down an experience that seems authentic to them.

Once a person has lost insight, it’ll be very difficult to convince them that what they’re experiencing isn’t happening. Trying to argue with them may agitate and even enrage the person. Making them anxious could cause their hallucinations to get worse.

Instead, talk to the person gently and reassuringly. You might say something like, “I understand that you see a dog in the corner of the room. Everything is going to be OK. You’re safe.” You might even say that the dog must have left already.

Remember that the person can’t control what they’re experiencing. Try to be as sympathetic as you can when you talk to them.

One approach that can help is to turn on all the lights in the room. Hallucinations are more likely to happen in dimly lit areas, and this can be caused by disease-related changes that affect the eyes.

Then, have the person really focus on what they’re seeing. That may reset their brain and help them see what’s actually in front of them.

If the person doesn’t have insight, try a distraction. Move them to a different room. Turn on the TV or play a game they like.

Try to keep your loved one as calm as possible. If they become very agitated or violent, call their doctor or 911.

After the hallucination passes, you can try to talk through the experience together. If the person has insight, it may be easier for them to understand and talk about what just happened.

Write down what happened during the hallucination. Note the time of day and what the person was doing when it started.

Taking notes each time it happens can help you identify the triggers. It could be related to the timing of medication, and your loved one might feel a sense of relief and control in knowing that pattern.

Call your loved one’s doctor as soon as you can and let them know about the hallucination.

Ask what you can do to stop it from happening again. This might include adjusting their medication dosage or adding an atypical antipsychotic drug to their medication regimen.

The most important thing you can do is to make sure your loved one is seeing their doctor. Treatments are available for both Parkinson’s motor symptoms and hallucinations.

Make sure the person is on the right type and dosage of medication. Some Parkinson’s drugs cause hallucinations and other side effects. Your loved one may need a medication change to resolve any side effects.

If a change in medication doesn’t help, they may need to take an atypical antipsychotic. These drugs can help to reduce hallucinations and other symptoms of Parkinson’s psychosis.

Another thing you can do is to make the home environment as safe and neat as possible. Keep bright lights on whenever possible. Remove any items, like piles of clothes, that might trigger a hallucination.

Also, ensure that the space is safe for the person to get around if they have movement issues. Secure any loose rugs and keep all walkways clear of clutter.

Caring for someone with a progressive condition like Parkinson’s disease can be challenging. Hallucinations only add to the stress of caregiving, especially if the person you’re caring for doesn’t have insight into what they’re experiencing.

The more you understand about your loved one’s condition, the easier it’ll be to care for them. Talk to their doctor and read up on Parkinson’s disease so you’re better equipped to respond when hallucinations occur.

Don’t forget to take care of yourself as well. Take regular breaks from caregiving to relax and do the things you enjoy. By tending to your own needs, you’ll have more energy to devote to your loved one.

Hallucinations are common in people with Parkinson’s disease, especially as the condition progresses. Don’t try to talk your loved one out of what they’re seeing, hearing, or feeling. Be supportive and reassuring until the hallucination passes.

Keep in touch with their doctor to make sure your loved one is on the right medication and dosage. Work with their doctor to adjust your loved one’s medication so that it helps with movement symptoms without causing hallucinations.