A sensory perception in the absence of an actual external stimulus; to be distinguished from an illusion, which is a misperception or misinterpretation of an external stimulus. Hallucinations may involve any of the senses. May occur in any of the senses.
An imaginary sensation perceived through any of the five senses; the result of alcohol withdrawal, drug use, severe illness, or schizophrenia. It occurs without any outside stimulus.
A false perception of reality; may be visual, auditory, or olfactory.
A sensory perception that has no environmental stimulus to bring it about. The most common is auditory. Psychotic persons may experience taste or small. Visual are very rare except in organic psychosis.
An experience of seeing an imaginary scene or hearing an imaginary sound as clearly as if it were really there.
Sights, sounds, or smells that do not exist, but are created by the mind of a drug user.
Apparent perception of something that is not, in fact, present (as opposed to an illusion, which is a misinterpretation of something that is present); a common symptom of psychosis. Hallucinations may be labeled by the main sense involved, such as auditory (as in hearing voices), visual (as in seeing objects), haptic or tactile (as in touching or feeling objects), olfactory (smelling), and gustatory (tasting), as well as somatic (perception within the body, such as feeling a current of electricity). Drugs or chemicals that induce hallucinations are called hallucinogens.
Perception of something that is not actually present; it may be visual (seeing objects that are not present), auditory (hearing noises that are not present), olfactoiy, gustatory, or tactile. Hallucinations are a common symptom of severe mental illness (e.g., schizophrenia); they also occur following injury to the head, in delirium accompanying severe illness, in delirium tremens in toxic states, and from the use of hallucinogens.
Subjective perception of events and sensations for which there is no external basis.
False perceptions in any of the senses in a person who is awake, but the perceptions are not based on an external reality. Examples include hearing voices of the dead, feeling as if insects are crawling under the skin (formication), or seeing visions of people who are elsewhere. Hallucinations are sometimes but not always a sign of a severe mental disorder. Hallucinations may be due to an adverse effect of a medication, substance abuse, or drug withdrawal.
A false perception of something that is not really there. Hallucinations may be visual, auditory, tactile, gustatory (of taste), or olfactory (of smell). They may be provoked by psychological illness (such as schizophrenia) or physical disorders in the brain (such as temporallobe epilepsy) or they may be caused by drugs or sensory deprivation. Hallucinations should be distinguished from dreams and from illusions (since they occur at the same time as real perceptions).
False perceptions arising without an adequate external stimulus, as opposed to illusions, which are misinterpretations of stimuli arising from an external object. Hallucinations come from ‘within’, although the affected individual may see them as coming from ‘without’. Nevertheless, they may occur at the same time as real perceptions, and may affect any sense (vision, hearing, smell, taste, touch, etc.).
A false perception having no relation to reality and not accounted for by any exterior stimulus; a dreamlike (or nightmarish) perception occurring while awake. It may be visual (especially in medical illnesses or drug withdrawal syndromes), auditory (especially in psychoses), tactile, gustatory, or olfactory. Affected patients typically appear confused and agitated. They are unable to distinguish between the real and the imaginary.
A deceptive or distorted perception of objects, sounds, or events that appears to be genuine. Hallucinations typically arise from the influence of drugs or mental disorders.
Hallucinations refer to perceptions that arise in the absence of any external stimuli. Auditory hallucinations, such as hearing voices, are a key symptom of schizophrenia, but can also be caused by manic-depressive illness and certain brain disorders. Visual hallucinations are often experienced during states of delirium induced by physical illnesses (like pneumonia) or alcohol withdrawal (delirium tremens). Hallucinogenic drugs are another typical cause of visual hallucinations. Hallucinations of smell are linked with temporal lobe epilepsy. Tactile and taste hallucinations are less common and mainly occur in individuals with schizophrenia. People undergoing sensory deprivation or intense physical stress sometimes experience temporary hallucinations.
A visual hallucination that may involve seeing deceased family members or, in cases like delirium tremens, seeing snakes, spiders, and other creepy-crawlies.