Yes, hallucinations are common in dementia and often treatable

Hallucinations — seeing, hearing, or sensing things that are not there — happen in many types of dementia, especially in the middle and later stages. They are not a sign that someone is "going crazy." They are a symptom caused by changes in the brain, the same way memory loss is. Between 10 and 50 percent of people with dementia experience hallucinations at some point, depending on the type of dementia and how far it has progressed.

The good news is that hallucinations often respond to treatment. A doctor can identify what is causing them — sometimes it is the dementia itself, sometimes it is medication, infection, or another medical condition — and work toward reducing them. Understanding what hallucinations look like in dementia, and when to call a doctor, helps you support someone and get help quickly.

Key Takeaways

  • Hallucinations in dementia are caused by brain changes, not by psychiatric illness, and they are a medical symptom that doctors can address.
  • The person may see people or animals that are not there, hear voices or music, or feel sensations on their skin — and they believe these experiences are real.
  • Hallucinations can be triggered or made worse by infection, medication side effects, poor lighting, fatigue, or a change in routine.
  • Tell the doctor about hallucinations at the next visit, or sooner if the person becomes frightened, aggressive, or unable to care for themselves.
  • Do not argue that the hallucination is not real; instead, stay calm, redirect attention, and check for medical causes like urinary tract infection.

What hallucinations look like in dementia

Hallucinations in dementia are usually visual — the person sees something. They might see a person standing in the room, an animal, or objects moving. Some people see people from their past, like a deceased spouse or parent. Others see strangers or threatening figures. The person believes what they see is real, even if you tell them it is not there.

Auditory hallucinations — hearing things — are less common but do occur. The person might hear voices, music, or sounds like knocking or footsteps. Tactile hallucinations — feeling things on the skin — can happen too; someone might feel insects crawling, or hands touching them. Rarely, people experience hallucinations of taste or smell.

The hallucinations are not dreams or confusion about what they see on television. The person is awake and alert, and the experience feels completely real to them. This is different from delusions, which are false beliefs (like thinking someone has stolen their money) rather than false perceptions.

Which types of dementia cause hallucinations most often

Lewy body dementia causes hallucinations in up to 80 percent of people who have it, usually early on. The hallucinations tend to be detailed and vivid — people often see animals or people. Parkinson's disease dementia also frequently includes hallucinations, often of people or animals.

Alzheimer's disease can cause hallucinations, but they are less common than in Lewy body dementia and usually appear in later stages. Vascular dementia and frontotemporal dementia may include hallucinations, though they are not the main feature of these conditions.

If you know which type of dementia someone has, that information helps the doctor understand what to expect and how to treat it. If you do not know the type yet, tell the doctor about the hallucinations — they can help narrow down the diagnosis.

Medical causes that can trigger or worsen hallucinations

Sometimes hallucinations appear or get worse because of something other than the dementia itself. Urinary tract infections are a common culprit in older adults and can cause sudden confusion and hallucinations even without fever or pain. Respiratory infections, dehydration, and constipation can also trigger them.

Medications are another major cause. Anticholinergic drugs (used for bladder control, allergies, or Parkinson's symptoms), some pain relievers, sleep aids, and steroids can all cause hallucinations as a side effect. If hallucinations start after a new medication begins, tell the doctor — the dose may need to change or a different drug may work better.

Low blood sugar, low blood pressure, poor sleep, and pain can also trigger hallucinations or make them worse. A person who is tired, hungry, or in pain is more likely to hallucinate. Checking these basics — offering food and water, making sure they have slept, asking about pain — can sometimes reduce hallucinations before you call the doctor.

Environmental and situational triggers

The setting and routine matter. Poor lighting makes hallucinations more likely — shadows and dim light can look like people or animals. Turning on lights, opening curtains, or using a nightlight can help. Loud or confusing noise — a television playing, multiple conversations, or unfamiliar sounds — can also trigger hallucinations.

Changes in routine or environment increase the risk. A move to a new room, a visit from someone unfamiliar, or a change in caregiver can be stressful enough to bring on hallucinations. Fatigue and overstimulation — too much activity, too many visitors, or a busy day — often lead to hallucinations later in the day or evening.

Keeping the environment calm, predictable, and well-lit, and maintaining a consistent routine, can reduce how often hallucinations happen. If you notice they occur at a certain time of day or in certain situations, mention that pattern to the doctor.

How to respond when someone is hallucinating

Stay calm and do not argue. Telling the person "that is not real" or "you are imagining things" does not work and often makes them more upset. To them, the hallucination is real. Instead, acknowledge their experience: "I see you are upset. I am here with you."

Redirect their attention gently. Offer a snack, suggest a walk, turn on music, or move to a different room. Sometimes a change of scenery breaks the hallucination. If they are frightened, stay close and speak in a calm, reassuring voice. Do not touch them suddenly if they are startled.

If the hallucination makes them aggressive or unsafe — if they try to hit you, run away, or hurt themselves — step back and call for help. Do not try to restrain them. If they are in when ready danger, call 911.

When to contact the doctor

Tell the doctor about hallucinations at the next scheduled visit if they are mild, happen rarely, and do not cause distress or unsafe behavior. Describe what the person sees or hears, when it happens, how long it lasts, and whether anything seems to trigger it.

Call the doctor sooner — the same day or the next morning — if hallucinations are new, frequent, or getting worse; if the person is frightened or aggressive; if they refuse to eat or drink; or if they try to harm themselves or others. Also call if hallucinations started right after a new medication began.

Go to an emergency room or call 911 if the person is in when ready danger, has stopped responding, has a high fever, or is having severe confusion along with the hallucinations. These can be signs of a serious infection or other medical emergency.

Treatment options the doctor may discuss

The doctor will first look for treatable causes — infection, medication side effects, low blood sugar, dehydration, or pain. If a urinary tract infection is found, antibiotics often stop the hallucinations. If a medication is the cause, the doctor may lower the dose, switch to a different drug, or stop it.

If hallucinations are caused by the dementia itself, the doctor may prescribe an antipsychotic medication. These drugs can reduce hallucinations, but they carry risks in older adults with dementia, including increased stroke risk and higher mortality in some cases. The doctor will weigh the benefits against the risks and use the lowest dose for the shortest time needed.

Non-medication approaches — good lighting, a calm environment, consistent routine, and activities that engage the person — are always part of the plan. Some people benefit from reality orientation (gently reminding them of the date, place, and who you are), while others do better with validation (accepting their experience without correcting it).

Frequently Asked Questions

Can hallucinations in dementia be cured?

Hallucinations caused by infection, medication, or other treatable conditions often go away once the cause is addressed. Hallucinations caused by the dementia itself may be reduced with medication or environmental changes, but they may not disappear completely. The goal is to reduce them enough that the person is safe and comfortable.

Does seeing hallucinations mean dementia is getting worse?

Hallucinations can appear at any stage of dementia, but they are more common as the disease progresses. New hallucinations do not always mean the dementia is advancing rapidly — they can also signal an infection or medication problem. The doctor can help determine what is causing them.

Should I tell the person they are hallucinating?

No. Arguing that the hallucination is not real upsets them and does not stop the hallucination. Instead, stay calm, acknowledge their feelings, and gently redirect their attention. If they ask whether you see it too, you can say "I do not see that, but I believe you do" without agreeing the thing is there.

Can I prevent hallucinations from happening?

You cannot prevent all hallucinations, but you can reduce how often they happen by keeping the environment well-lit and calm, maintaining a regular routine, making sure the person eats and sleeps well, and checking for signs of infection or pain. Avoiding overstimulation and sudden changes also helps.

Is it safe to give someone medication to stop hallucinations?

Antipsychotic medications can reduce hallucinations, but they carry risks in older adults with dementia. The doctor will discuss whether the benefits outweigh the risks for that person, and will use the lowest effective dose. Regular check-ins are important to make sure the medication is helping and not causing harm.