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What It Means

What Hallucinations Mean

Hallucinations are sensory experiences that seem real but happen without an external stimulus. A person may hear, see, feel, smell, or taste something that is not actually present, and they may not recognize the experience as unreal. Hallucinations are a symptom rather than a diagnosis, so their meaning depends on the person’s health, medicines, substances, sleep, and other symptoms.

Types of hallucinations

TypeWhat it may involve
AuditoryHearing voices, sounds, or music that are not externally present
VisualSeeing people, objects, lights, or shapes that are not there
TactileFeeling touch, movement, crawling, or pressure without a physical cause
OlfactorySmelling odors that others cannot detect
GustatoryTasting flavors without an identifiable source

An illusion is different because it is a misinterpretation of a real stimulus, such as mistaking a coat on a chair for a person. A delusion is a fixed belief that is not supported by reality, rather than a sensory experience. Hallucinations and delusions can occur together, but they are not the same thing.

Emergency Warning Signs

Emergency Warning Signs

Get urgent help

Hallucinations can be an emergency

Seek emergency help now if hallucinations involve immediate danger, commands to harm yourself or someone else, severe confusion, inability to stay safe, sudden weakness or trouble speaking, a seizure, high fever, severe headache, head injury, or possible poisoning or overdose. Do not leave a person at risk alone; contact local emergency services.

Possible Causes

Possible Causes of Hallucinations

Hallucinations are a symptom, not a diagnosis. What causes hallucinations can depend on the sensory type, when the experience began, how often it happens, other symptoms, medicines, substance use, sleep, and a person’s medical history.

  • Mental health conditions, including schizophrenia-spectrum disorders, severe depression, mania, or psychosis.
  • Dementia and other conditions affecting memory or brain function.
  • Delirium from infection, fever, metabolic illness, or another acute medical problem.
  • Neurological conditions such as seizures, Parkinson’s disease, migraine, or brain injury.
  • Medicines, interactions, intoxication, or withdrawal from alcohol or other substances.
  • Severe sleep deprivation or experiences occurring while falling asleep or waking.
  • Reduced vision or hearing, which can contribute to visual or auditory hallucinations.

Visual hallucinations or tactile hallucinations, especially when they begin suddenly, deserve medical attention. New hallucinations in an older adult, or hallucinations accompanied by confusion, fever, weakness, or another physical illness, may have a medical or neurological cause and should not be assumed to be schizophrenia hallucinations.

Duration Triage Table

What Hallucinations May Mean by Duration

A single brief episode and recurring or persistent hallucinations can have very different causes. Sudden changes or associated physical symptoms generally increase the need for prompt assessment, but duration alone cannot identify the cause.

PatternWhat it may suggestWhat to do
Acute: minutes to hoursMedication or substance effects, sleep transition, seizure, migraine, delirium, or another sudden medical problemSeek prompt assessment, especially with confusion, fever, neurological symptoms, or substance exposure
Subacute: days to weeksNew mental health symptoms, infection, medication change, withdrawal, or evolving neurological illnessArrange a medical evaluation soon and record timing, triggers, and associated symptoms
Chronic or recurrent: weeks to monthsOngoing psychiatric, neurological, dementia-related, sensory, medication, or substance-related causesArrange clinical assessment even if episodes are familiar or not distressing

Relief Tips

What to Do During Hallucinations

  • Move to a calm, familiar, and well-lit setting if possible.
  • Speak slowly and calmly, and acknowledge that the experience feels real or frightening.
  • Do not argue about what the person sees or hears, and do not reinforce unsafe beliefs.
  • Avoid alcohol and recreational drugs, and review any recent medication or dose changes with a clinician.
  • Do not drive or operate machinery while hallucinations affect judgment or perception.
  • Stay with the person or involve a trusted support person if there is any safety concern.

When to See a Doctor

When to See a Doctor About Hallucinations

Arrange a medical appointment for any new, recurring, persistent, or distressing hallucinations, even when the person feels safe. Seek prompt assessment after a medication change, substance exposure, illness, or head injury, because these events may help explain the symptom.

What to record before the appointment

Record whether the experience was auditory, visual, tactile, olfactory, or gustatory; when it began; how long it lasted; how often it occurs; possible triggers; sleep patterns; alcohol or drug exposure; medicines and recent changes; physical symptoms; and any effect on safety. Evaluation may include a mental and physical health assessment, medication and substance review, neurological examination, and targeted tests based on the presentation. Do not stop prescribed medication without medical advice.

Complications

Possible Complications

  • Fear, anxiety, or emotional distress.
  • Sleep disruption and worsening fatigue.
  • Withdrawal from usual activities or difficulty maintaining relationships.
  • Problems with work, school, self-care, or day-to-day decisions.
  • Accidental injury when responding to a perceived threat or trying to escape.
  • Risk of harm to self or others when hallucinations include dangerous commands or severe confusion.

Diseases & Conditions

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