Hallucinations are abnormal sensory perceptions that occur while a person is awake and conscious and are unrelated to outside events; in other words, seeing or hearing things that aren't there.
Alternative Names
Sensory hallucinations
Considerations
Common hallucinations include:
Hearing voices when no one has spoken
Seeing patterns, lights, beings or objects that aren't there
Feeling a crawling sensation on the skin
Hallucinations related to smell or taste are rare.
Many recreational drugs, including psychedelic drugs such as LSD and certain potent types of marijuana, may cause hallucinations. Hallucinations related to these drugs tend to be visual and may include geometric patterns or haloes around lights. People who have such visual hallucinations after taking drugs usually recognize that their perception is distorted.
Auditory hallucinations are more common in psychotic conditions such as schizophrenia, although they may sometimes be associated with high doses of cocaine, amphetamine, or other stimulant. High doses of stimulant drugs frequently cause a sensation of bugs crawling on or immediately under the skin.
In some cases, hallucinations, may be normal. For example, hearing the voice of, or briefly seeing, a loved one who has recently died can be a part of the grieving process.
Common Causes
There are numerous medical and psychiatric causes of hallucinations. Common causes include:
Fever, particularly in children and the elderly
Intoxication or withdrawal from such drugs as marijuana, LSD, cocaine or crack, heroin, and alcohol
If someone begins to hallucinate and is detached from reality, a prompt medical evaluation should be sought, since many medical conditions that can cause hallucinations may quickly become emergencies. A person who is hallucinating may become agitated, paranoid, and frightened, and should not be left alone.
Call your health care provider, go to the emergency room, or call the local emergency number (such as 911) if someone appears to be hallucinating and is unable to distinguish hallucinations from reality.
What to expect at your health care provider's office
The health care provider will perform a physical examination and will obtain a medical history. Blood may be drawn for testing.
Schizophrenia (1 image)
Average Rating:
(Doctor-Reviewed information)
Schizophrenia is a mental disorder. It difficult for a person to tell the difference between real and unreal experiences, to think logically, to have normal emotional responses to others, and to behave normally in social situations. Reviewer: Paul Ballas, D.O., Department of Psychiatry, Thomas Jefferson University Hospital, Philadelphia, PA. Review provided by VeriMed Healthcare Network.Date: 05/08/2006
Psychosis(Doctor-Reviewed information)
Psychosis is a loss of contact with reality, typically including delusions (false ideas about what is taking place or who one is) and hallucinations (seeing or hearing things which aren't there. Reviewer: Paul Ballas, D.O., Department of Psychiatry, Thomas Jefferson University Hospital, Philadelphia, PA. Review provided by VeriMed Healthcare Network.Date: 05/17/2006
Alcoholism (7 images)
Average Rating:
(Doctor-Reviewed information)
Alcoholism is an illness marked by drinking alcoholic beverages at a level that interferes with physical health,¿mental health, and social, family, or occupational responsibilities. Alcoholism is divided into 2 categories: dependence and abuse. People with alcohol dependence, the most severe alcohol disorder, usually experience tolerance and withdrawal. Tolerance is a need for markedly increased amounts of alcohol to achieve intoxication or the desired effect. Withdrawal occurs when alcohol is discontinued or intake is decreased. Alcohol dependents spend a great deal of time drinking alcohol, and obtaining it. Alcohol abusers may have legal problems such as drinking and driving. They may also¿have problems with binge drinking (drinking 6 or more drinks at one sitting. People who are dependent on or abuse alcohol continue to drink it¿despite evidence of physical or psychological problems. Those with dependence have more severe problems and a greater compulsion to drink. Reviewer: Paul Ballas, D.O., Department of Psychiatry, Thomas Jefferson UniversityHospital, Philadelphia, PA. Review provided by VeriMed Healthcare Network.Date: 05/08/2006
Marijuana intoxication(Doctor-Reviewed information)
Marijuana¿ ("pot) is the most commonly used illegal drug in the United States. The drug is primarily smoked, sometimes eaten. Its intoxicating effects include relaxation, sleepiness, and mild euphoria (getting high. Marijuana can cause undesirable side effects, which increase with higher doses. These side effects include dry mouth, red eyes, impaired perception and motor skills, decreased short-term memory, paranoia, mood swings, and hallucinations. The amount and effect of these side effects varies from individual to individual. Related topics: Drug abuse; Drug abuse and dependence; Drug abuse first aid. Reviewer: Eric Perez, MD, Department of Emergency Medicine, St. Luke's-Roosevelt Hospital Center, New York, NY. Review provided by VeriMed Healthcare Network.Date: 07/18/2007