Medically Reviewed by Zilpah Sheikh, MD on April 16, 2024
10 min read

Hallucinations are false perceptions, where you sense an object, person, or event even though it is not really there or didn't happen. It seems very real to you. Sometimes, you may know you're having a hallucination. Other times, you may be sure it's real.

If you're like most folks, you probably think hallucinations always have to do with seeing things that aren't really there. But there's a lot more to it. It could mean you touch or even smell something that doesn't exist. Hallucinations can involve any one or all of your senses: sight, sound, smell, touch, and taste.

There are many possible causes. Generally, they happen from chemical reactions in your body or changes in your brain. It could be a mental illness called schizophrenia, a nervous system problem such as Parkinson's disease, epilepsy, or several other things.

If you or a loved one has hallucinations and you don't know why, go see a doctor. You can get treatments to control them, but a lot depends on what's behind the trouble.

Hallucinations vs. delusions

A delusion is a false belief. You may think something is real when it isn't. But a delusion doesn't involve a sensory experience of something that isn't real.

Hallucinations vs. paranoia

Paranoia is a certain type of delusion. You will think other people are "out to get you" even though they aren't. You may feel without reason that others are being mean, unfair, or dishonest with you.

Hallucinations vs. illusions

An illusion happens when you misunderstand or misinterpret something that is real or that has actually happened. You might think that a black object is a cat when it isn't. An illusion is based on sensory inputs in the world. In hallucinations, you'll experience sensory inputs even though nothing is there.

Hallucinations can have many different causes. They may be temporary or ongoing. They may be caused by a mental health or neurological condition that affects your brain. Drugs including medicines also can cause them.

Hallucinations most often result from:

Schizophrenia. More than 70% of people with this illness get visual hallucinations, and 60%-90% hear voices. But some may also smell and taste things that aren't there.

Parkinson's disease. Up to half of people who have this condition sometimes see things that aren't there.

Alzheimer's disease and other forms of dementia, especially Lewy body dementia. They cause changes in the brain that can bring on hallucinations. It may be more likely to happen when your disease is advanced.

Migraines. About a third of people with this kind of headache also feel an "aura," a type of visual hallucination. It can look like a multicolored crescent of light.

Brain tumor. Depending on where it is, it can cause different types of hallucinations. If it's in an area that has to do with vision, you may see things that aren't real. You might also see spots or shapes of light. Tumors in some parts of the brain can cause hallucinations of smell and taste.

Charles Bonnet syndrome. This condition causes people with vision problems such as macular degeneration, glaucoma, or cataracts to see things. At first, you may not realize it's a hallucination, but eventually, you figure out that what you're seeing isn't real.

Epilepsy. The seizures that go along with this disorder can make you more likely to have hallucinations. The type you get depends on which part of your brain the seizure affects.

Hallucinations and your mental health

Many mental health conditions may involve hallucinations. It's most common to hear voices. Schizophrenia is the main one. But other conditions fall under the spectrum of schizophrenia including:

  • Schizotypal personality disorders
  • Delusional disorder
  • Brief psychotic disorder
  • Schizophreniform disorder
  • Schizoaffective disorder

Other mental health conditions that may involve hallucinations are:

  • Bipolar disorder
  • Major depression with psychotic features or psychotic depression
  • Postpartum psychosis
  • Posttraumatic stress disorder (PTSD)

Drug hallucinations

Many medicines your doctor may prescribe can cause hallucinations or make hallucinations worse. Some recreational drugs also can cause hallucinations. 

Hallucinations from medicine are more likely as you get older. The hallucinations may be related to the amount of medicine you're taking. Usually, you'll stop having them if you lower the dose or stop taking the medicine. You should never stop taking medicine without talking to your doctor. If you're having hallucinations and think it's related to your medicine, reach out for help.

Hallucinations and sleep

Hallucinations can happen just before you fall asleep or right after you wake up. They may get better if you get more sleep or sleep at regular times. Avoiding alcohol or other drugs may help, too. If you're having hallucinations related to sleeping, and especially if it's causing you anxiety or trouble sleeping, see a doctor for help. You may need a sleep study. If you're having sleep hallucinations and are severely tired during the day, you could have narcolepsy.

Hallucinations also can happen during sleep paralysis. This is a condition right after falling asleep or waking up when you can't move or speak. You may think you hear, see, feel, or sense something while you're unable to do anything about it.

Other causes for hallucinations

Many other conditions or scenarios can make you hallucinate. These include:

  • High fever
  • Dehydration, especially if it's severe
  • Trauma
  • Severe pain
  • Grief
  • Infections, such as urinary tract infections (UTIs)

When hallucinations are short-term or caused by a temporary issue, they aren't always too concerning. But if you are hallucinating and don't know why or if you are having an acute medical issue, get help right away.

Hallucinations can affect any of your five senses and have several types.

Visual hallucinations

You'll see things that aren't there. It could be just about anything — objects, people, animals, lights, or shapes. For example, you might:

  • See things others don’t, such as insects crawling on your hand or on the face of someone you know
  • See objects with the wrong shape
  • See things moving in ways they usually don’t

Sometimes, they look like flashes of light. A rare type of seizure called "occipital" may cause you to see brightly colored spots or shapes. Other causes include:

  • Irritation in the visual cortex, the part of your brain that helps you see
  • Damage to brain tissue (the doctor will call it lesions)
  • Schizophrenia
  • Schizoaffective disorder
  • Depression
  • Bipolar disorder
  • Delirium (from infections, drug use and withdrawal, or body and brain problems)
  • Dementia
  • Parkinson’s disease
  • Seizures
  • Migraines
  • Brain lesions and tumors
  • Sleep problems
  • Drugs that make you hallucinate
  • Metabolism problems
  • Creutzfeldt-Jakob disease

Auditory hallucinations

You may sense that the sounds are coming from inside or outside your mind. You might hear the voices talking to each other or feel like they're telling you to do something. Causes may include:

Tactile hallucinations

You might think you're being tickled even when no one else is around, or you may feel like insects are crawling on or under your skin. You could feel a blast of hot air on your face that isn't real. Possible causes include:

  • Schizophrenia
  • Schizoaffective disorder
  • Drugs that make you hallucinate
  • Delirium tremens
  • Alcohol
  • Alzheimer's disease
  • Lewy body dementia
  • Parkinson's disease

Olfactory hallucinations

You may think the odor only you can smell is coming from something around you, or that it's coming from your own body. Causes can include:

Gustatory hallucinations

You may feel that something you eat or drink tastes strange. A common one is to feel that things taste like metal. Causes can include:

  • Temporal lobe disease
  • Brain lesions
  • Sinus diseases
  • Epilepsy

Presence hallucinations

You will feel as if someone is in the room with you even when nobody is there.

Proprioceptive hallucinations

You may sense that your body is moving in ways that it is not. For example, you may feel as though you are flying or floating in midair.

Hypnopompic and hypnagogic hallucinations

A hypnopompic hallucination happens right after you wake up. A hypnagogic hallucination happens just before you fall asleep. These hallucinations happen most often when you have narcolepsy.

First, your doctor needs to find out what's causing your hallucinations. They'll ask about your medical history and do a physical exam. Then they'll ask about your symptoms.

They may need to do tests to help figure out the problem. For instance, an electroencephalogram (EEG) checks for unusual patterns of electrical activity in your brain. It could show if your hallucinations are due to seizures.

You might get an MRI, which uses powerful magnets and radio waves to make pictures of the inside of your body. It can find out if a brain tumor or something else, such as an area that's had a small stroke, could be to blame.

Your doctor will treat the condition that's causing the hallucinations. This can include things such as:

  • Medication for schizophrenia or dementias such as Alzheimer's disease
  • Anti-seizure drugs to treat epilepsy
  • Treatment for macular degeneration, glaucoma, and cataracts
  • Surgery or radiation to treat tumors
  • Drugs called triptans, beta-blockers, or anticonvulsants for people with migraines

Your doctor may prescribe pimavanserin (Nuplazid). This medicine treats hallucinations and delusions linked to psychosis that affect some people with Parkinson’s disease.

Sessions with a therapist can also help. For example, cognitive behavioral therapy, which focuses on changes in thinking and behavior, helps some people manage their symptoms better.

Dealing with drug hallucinations

If you're dealing with hallucinations related to psychedelic or other drug use, you could have what's called a "bad trip." You may feel like you're losing yourself or losing your mind. You may see things that scare you or lose your sense of self.

Some people say you can avoid this by setting certain rules for yourself. Sometimes, people are able to turn these experiences into something they learn from or are challenged by.

When you have hallucinations, it's important to see a doctor for help. But you can also use strategies to help cope with seeing or hearing things that aren't there. Try different things and see what works.

Understand your hallucinations. Learning more about hallucinations may help you feel more in control. You can start to know when they're causing problems and change the way you think about them so you feel more in control.

Ask yourself questions. When did the hallucinations start? Do they relate to something in your life? When do they come up? How do they make you feel?

Track your hallucinations. Try keeping a diary or jotting down notes so you can look for patterns. You may start to notice triggers, which you can share with your doctor.

Talk to them. Work to build a positive relationship with your hallucinations. Try different approaches to talking or responding to them. For example, try challenging them, being kind to them, or responding to them neutrally.

Distract yourself. If you want to ignore your hallucinations, try to find ways to block them out. Focus on the things in your environment that you can sense. Concentrate on your breathing. Do something else such as exercise, cook, or listen to music.

Join a support group. Find other people who know what it's like. They can help you feel less alone and find new ways to deal with it.

Find a faith community. If you think it might help, reach out to people in your faith community or find a new place to worship. You may find both a supportive community and new meaning.

Take care of yourself. Do your best to get enough sleep, eat well, and relax. Spend time outside and exercise.

Consider a service dog. Psychiatric service dogs can help with a variety of tasks when you have mental health conditions including hallucinations. A dog can help you tell whether what you're seeing is real or not. For example, they can greet people who walk into the room to help you know they're real.

If someone you care about is having hallucinations, here are some things you may do to help:

  • Work to understand their hallucinations and if they are causing upset or hazards.
  • Offer reassurance and a comforting touch if appropriate.
  • Avoid arguing about whether the hallucination is real.
  • Don't intervene unless you need to for their own protection.
  • Don't try to reason with them.
  • Acknowledge what they're seeing in a calm manner.

If a loved one is having hallucinations such that they don't know what's real, it's important to see a doctor, especially if you don't know the cause. Some conditions that cause hallucinations are medical emergencies.

Hallucinations are false perceptions in which you'll think you're seeing, hearing, touching, or tasting something that isn't there. Many things can cause them, and they may be temporary or ongoing. If you or a loved one is having hallucinations, see a doctor to find out the cause and next steps.

Can anxiety cause hallucinations?

Yes, it's possible for anxiety to trigger hallucinations. Hallucinations can also make anxiety worse. If you're struggling with anxiety and hallucinations, seek help from a mental health professional.

Can stress cause hallucinations?

Any intense emotion can lead to hallucinations, especially if you are prone to them.

Can a person recover from hallucinations?

It depends on the reason for your hallucinations. Many people do have hallucinations that are temporary or happen rarely. You'll need to understand what's causing the hallucinations and work to treat the underlying cause.

Can hallucinations kill you?

Hallucinations by themselves can't kill you. But they could be dangerous or even life-threatening. For example, studies have associated auditory and visual hallucinations with suicide planning and attempts.