Types of hallucinations in schizophrenia: auditory, visual, tactile, and more

A hallucination is a sensory experience that has no source in the external world but feels just as real as any other perception. In schizophrenia, hallucinations are one of the defining "positive" symptoms — meaning they are experiences added to ordinary perception. The National Institute of Mental Health (NIMH) notes that hallucinations occur in roughly 60–80% of people with schizophrenia at some point in their illness, but the type, frequency, and content vary enormously.

Auditory hallucinations

Auditory hallucinations are the most common type, reported by about 70% of people with schizophrenia. Most often they are voices, but they can also be sounds: knocking, music, footsteps, or vague background noise.

Voices: who, what, and how

Voices vary along several dimensions clinicians find useful to assess:

• Number — one voice, two voices in dialogue, or many.
• Identity — strangers, recognised people (living or deceased), entities (God, the devil), or unknown.
• Content — running commentary on actions, criticism, commands, conversation, or fragments.
• Location — outside the head (more characteristic of psychosis) or inside the head.
• Tone — neutral, mocking, threatening, kind.

Two patterns are particularly characteristic of schizophrenia: third-person voices (two or more voices talking about the person) and running commentary (a voice describing the person's actions as they happen). These were once called "first-rank symptoms" and remain clinically important pointers.

Command hallucinations

Voices that order the person to do something deserve careful attention. Most are not acted on, but they are a source of significant distress and warrant a clinical conversation about safety planning. Therapy approaches such as CBT for voices work directly with the beliefs that make commands feel compelling.

Visual hallucinations

Visual hallucinations occur in roughly 16–72% of people with schizophrenia depending on the study, with most putting the figure around 25–30%. They are less common than auditory hallucinations and tend to be more strongly associated with severe illness, drug use, or medical contributors.

Common forms include:

• Seeing figures, faces, or shadows in the periphery
• Distortions of familiar objects (a wall appearing to breathe)
• Fully formed visions of people, animals, or scenes
• Brief flashes of light or geometric patterns

Because vivid visual hallucinations are also common in delirium, dementia with Lewy bodies, drug intoxication, and certain seizure disorders, clinicians take them as a prompt to rule out non-psychiatric causes.

Tactile (somatic) hallucinations

Tactile hallucinations involve sensations on or under the skin: tingling, burning, electric shocks, the feeling of insects crawling (formication), or a sensation that someone is touching the person. They are reported by around 5–20% of people with schizophrenia.

Tactile hallucinations are particularly common in stimulant-induced psychosis (especially methamphetamine), where the formication sensation can become severe enough to cause skin damage from scratching. See our guide on drug-induced psychosis for more.

Olfactory hallucinations (smell)

Smelling odours that aren't there — usually unpleasant ones such as smoke, rotting food, or chemicals — affects a smaller proportion of patients. Pleasant olfactory hallucinations are rare. Because olfactory hallucinations are also a feature of temporal lobe seizures and certain neurological conditions, clinicians often request a workup when they appear suddenly without other psychotic symptoms.

Gustatory hallucinations (taste)

Tasting things that aren't there — frequently described as metallic, bitter, or chemical — is the rarest form. Gustatory hallucinations sometimes accompany delusions about food being poisoned, which can lead to refusal to eat. They also overlap with side effects of some medications, so clinicians take a careful history before attributing them to psychosis.

Less commonly discussed types

Cenesthetic hallucinations

Sensations originating from inside the body — organs moving, blood flowing in unusual patterns, or strange internal pressures. They are uncommon but can be deeply distressing and are sometimes paired with somatic delusions.

Hypnagogic and hypnopompic hallucinations

These occur as a person is falling asleep or waking up. They are extremely common in the general population (roughly 25–30% of adults experience them) and are not, by themselves, a sign of psychosis. Clinicians distinguish them from psychotic hallucinations by their timing and the person's intact reality testing afterwards.

What hallucinations don't always mean

Hearing a voice once is not the same as having schizophrenia. Population studies summarised by NIMH and others suggest that 5–15% of the general population have heard a voice at some point in their lives without ever developing a psychiatric condition. The Hearing Voices movement has built a community around this insight. The clinical question is rarely "is the experience present?" but rather "how distressing is it, how often does it happen, and how much does it interfere with life?"

What contributes to hallucinations

Multiple factors can amplify or trigger hallucinations:

• Sleep deprivation — even one or two nights of severe sleep loss can trigger perceptual disturbances
• Substance use — cannabis, methamphetamine, hallucinogens, alcohol withdrawal
• Stress — a well-documented trigger for relapse in schizophrenia
• Medication non-adherence — one of the leading causes of relapse
• Sensory deprivation — even otherwise healthy people in extreme isolation can hallucinate

How treatment helps

Antipsychotic medication reduces the frequency and intensity of hallucinations for most people, though for a minority — roughly 30% — symptoms persist despite adequate trials of standard medication, a state called treatment-resistant schizophrenia, where clozapine becomes the next step. Psychosocial interventions like CBTp do not always make the hallucinations disappear, but they reliably reduce associated distress and the degree to which voices control behaviour.

The bigger picture

Hallucinations are not a moral failing, a sign of weakness, or evidence that someone is "crazy." They are a feature of how a particular brain is processing perception in a particular moment. With treatment, most people see meaningful reduction in their intensity and impact — and many find that learning to relate differently to the experience matters as much as silencing it altogether.

This article is for educational purposes only and is not medical advice, diagnosis, or treatment. Always consult a qualified mental health professional. If you or someone you know is in crisis, call or text 988 in the US, or your local emergency number.