Hallucinations involve sensing things such as visions, sounds, or smells that seem real but are not. These things are created by the mind.
Common hallucinations can include:
Sometimes, hallucinations are normal. For example, hearing the voice of or briefly seeing a loved one who recently died can be a part of the grieving process.
There are many causes of hallucinations, including:
A person who begins to hallucinate and is detached from reality should get checked by a health care professional right away. Many medical and mental conditions that can cause hallucinations may quickly become emergencies. The person should not be left alone.
Call your health care provider, go to the emergency room, or call 911 or the local emergency number.
A person who smells odors that are not there should also be evaluated by a provider. These hallucinations may be caused by medical conditions such as epilepsy and Parkinson disease.
Your provider will do a physical examination and take a medical history. They will also ask you questions about your hallucinations. For example, how long the hallucinations have been happening, when they occur, or whether you have been taking medicines or using alcohol or illegal drugs.
Your provider may take a blood sample for testing.
Treatment depends on the cause of your hallucinations.
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Freudenreich O, Brown HE, Holt DJ. Psychosis and schizophrenia. In: Stern TA, Fava M, Wilens TE, Rosenbaum JF, eds. Massachusetts General Hospital Comprehensive Clinical Psychiatry. 2nd ed. Philadelphia, PA: Elsevier; 2016:chap 28.
Kelly MP, Shapshak D. Thought disorders. In: Walls RM, Hockberger RS, Gausche-Hill M, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier; 2018:chap 100.
Reviewed By: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.