What are hallucinations?

A hallucination is when you see, hear, or feel things that are not real, even though they seem very real to you.

Hallucinations are not the same as illusions. Illusions are when you see or hear something and think it is something else. For example, you may see a lamp out of the corner of your eye and think it is a person. If you have a hallucination, you may feel someone touch your arm even though you are all alone.

What is the cause?

Some causes of hallucinations include:

  • Fever, especially in children and older adults
  • Serious illness such as liver failure, kidney failure, or brain cancer
  • Mental problems such as schizophrenia or bipolar disorder
  • Brain damage
  • Severe dehydration
  • Side effects of medicine
  • Severe lack of sleep
  • Severe stress
  • Drugs such as LSD, poisonous mushrooms, or PCP
  • Heavy alcohol use or withdrawal

You may have hallucinations right before you get a migraine or have a seizure.

What are the symptoms?

Hallucinations may involve any of the senses, such as:

  • Hearing voices when no one is speaking
  • Seeing things that are not there
  • Feeling things crawling on you or touching your body that are not there
  • Smelling scents that are not there
  • Tasting flavors that are not there

How are they diagnosed?

Your healthcare provider will ask about your symptoms, medical and family history, and any medicines you are taking. He will make sure you do not have a medical illness or drug or alcohol problem that could cause the symptoms. You may have tests or scans to help make a diagnosis.

If no medical cause can be found, you may be referred to a mental health professional for further testing.

How are they treated?

Treatment depends on the cause. If hallucinations are rare, or if they do not interfere with your life, no treatment may be needed.

Hallucinations caused by mental health problems such as schizophrenia can generally be controlled with medicine. If hallucinations are caused by medicine, changing how much or how often you take your medicine, or changing the medicine may correct the problem. Treating alcohol and substance abuse may prevent further hallucinations.

Hallucinations can be scary for the person having them and for anyone around them. When someone is having hallucinations, it is important to keep calm. If hallucinations are new, intense, or involve injury, get medical help right away.

Get emergency care if you or a loved one has serious thoughts of suicide or self-harm, violence, or harming others.

Developed by RelayHealth.
Adult Advisor 2015.1 published by RelayHealth.
Last modified: 2013-05-03
Last reviewed: 2013-05-03
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
Copyright ©1986-2015 McKesson Corporation and/or one of its subsidiaries. All rights reserved.

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