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Hallucinations
Sensory hallucinations
Hallucinations involve sensing things such as visions, sounds, or smells that seem real but are not. These things are created by the mind.
Considerations
Common hallucinations can include:
- Feeling sensations in the body, such as a crawling feeling on the skin or the movement of internal organs.
- Hearing sounds, such as music, footsteps, windows or doors banging.
- Hearing voices when no one has spoken (the most common type of hallucination). These voices may be positive, negative, or neutral. They may command someone to do something that may cause harm to themselves or others.
- Seeing patterns, lights, beings, or objects that are not there.
- Smelling an odor.
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.
Causes
There are many causes of hallucinations, including:
-
Being drunk or high, or coming down from such drugs like
marijuana
,
LSD
, cocaine (including crack), PCP, amphetamines, heroin, ketamine, and alcohol
Marijuana
Substance use is the continued use of alcohol, illegal drugs, or the misuse of prescription or over-the-counter drugs with negative consequences. Th...
Read Article Now Book Mark ArticleLSD
Substance use is the continued use of alcohol, illegal drugs, or the misuse of prescription or over-the-counter drugs with negative consequences. Th...
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Delirium
or
dementia
(visual hallucinations are most common)
Delirium
Delirium is sudden severe confusion due to rapid changes in brain function that occur with physical or mental illness.
Read Article Now Book Mark ArticleDementia
Dementia is a loss of brain function that occurs with certain diseases. It affects memory, thinking, language, judgment, and behavior.
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Epilepsy
that involves a part of the brain called the temporal lobe (odor hallucinations are most common)
Epilepsy
Epilepsy is a brain disorder in which a person has repeated seizures over time. Seizures are episodes of uncontrolled and abnormal firing of brain c...
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Fever
, especially in children and the older people
Fever
Fever is the temporary increase in the body's temperature in response to a disease or illness. A child has a fever when the temperature is at or abov...
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Narcolepsy
(disorder that causes a person to fall into periods of deep sleep)
Narcolepsy
Narcolepsy is a nervous system problem that causes extreme sleepiness and attacks of daytime sleep.
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Mental disorders, such as
schizophrenia
and psychotic depression
Schizophrenia
Schizophrenia is a mental disorder that makes it hard to tell the difference between what is real and not real. It also makes it hard to think clearl...
Read Article Now Book Mark Article - Sensory problem, such as blindness or deafness
-
Severe illness, including liver failure,
kidney failure
,
HIV/AIDS
, and brain cancer
Kidney failure
Acute kidney failure is the rapid (less than 2 days) loss of your kidneys' ability to remove waste and help balance fluids and electrolytes in your b...
Read Article Now Book Mark ArticleHIV/AIDS
Human immunodeficiency virus (HIV) is the virus that causes AIDS. When a person becomes infected with HIV, the virus attacks and weakens the immune ...
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When to Contact a Medical Professional
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 your local emergency number (such as 911).
A person who smells odors that are not there should also be evaluated by a provider. These hallucinations may be caused by a serious medical condition.
What to Expect at Your Office Visit
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.
References
American Psychiatric Association. Diagnostic and statistical manual of mental disorders . 5th ed. Arlington, VA: American Psychiatric Publishing. 2013.
Freudenriech O, Brown HE, Holt DJ. Psychosis and schizophrenia. In: Stern TA, Fava M, Wilens TE, Rosenbaum JF, Biederman J, Rauch SL, eds. Massachusetts General Hospital Comprehensive Clinical Psychiatry . 2nd ed. Philadelphia, PA: Elsevier Mosby; 2016:chap 28.
Hockberger RS, Richards JR. Thought disorders. In: Marx JA, Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice . 8th ed. Philadelphia, PA: Elsevier Saunders; 2013:chap 110.
Review Date: 2/2/2016
Reviewed By: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
