Hallucinations

A hallucination is an experience involving one or more senses without an outside source. You may hear a voice when nobody has spoken, see a person who is not there, or feel something touching your skin.

The experience can seem completely real. Some people recognise that it may be a hallucination, while others do not. Hallucinations are different from misinterpreting something that is present, such as mistaking a coat for a person in dim light.

Having a hallucination does not automatically mean you have a mental health condition. Hallucinations can happen around sleep, after severe sleep loss, because of a medicine or substance, or alongside problems affecting vision, hearing, the brain, or physical health.

Hallucinations can affect any sense:

• Hearing: voices, music, footsteps, knocking, or other sounds
• Seeing: people, animals, lights, shapes, shadows, or detailed scenes
• Touch: crawling, movement, pressure, or being touched
• Smell: smoke, burning, chemicals, food, or unpleasant odours
• Taste: an unexplained flavour, sometimes metallic or bitter

Voices may speak to you, discuss you, or give instructions. They may be comforting, neutral, critical, or frightening. Hearing a voice does not by itself show what is causing it.

Experiences while falling asleep are called hypnagogic hallucinations. Those that happen while waking are called hypnopompic hallucinations. These can be brief and may occur in otherwise healthy people.

Common situations include severe sleep loss, high fever, intense stress, and experiences around falling asleep or waking. Some people also sense or hear someone who has died during bereavement. This does not necessarily mean they are unwell.

Prescription medicines can sometimes contribute, especially after a medicine is started, stopped, or changed. Alcohol and recreational drugs may cause hallucinations during use or withdrawal. Do not stop a prescribed medicine suddenly without medical advice.

Other possible causes include significant sight or hearing loss. For example, people with reduced vision may see detailed images that are not present. This is sometimes called Charles Bonnet syndrome.

Hallucinations can also occur with migraine, epilepsy, Parkinson's disease, dementia with Lewy bodies, or other conditions affecting the brain. Mental health conditions involving psychosis may cause hallucinations, sometimes alongside strongly held unusual beliefs or confused thinking. Severe depression, bipolar disorder, and trauma-related conditions can also be involved.

Causes needing urgent assessment include delirium, which is a sudden change in attention and awareness caused by illness, medication, surgery, or another physical problem. Alcohol or sedative withdrawal, poisoning, seizures, serious infection, head injury, and some complications after childbirth can also cause sudden hallucinations.

Call emergency services now if:

• A voice is telling you to harm yourself or someone else, and you may act
• You or someone nearby cannot stay safe
• Hallucinations follow a seizure or serious head injury
• They occur with new weakness, facial drooping, or difficulty speaking
• They begin after childbirth with severe confusion, agitation, or unusual beliefs

Seek urgent same-day medical care for new hallucinations with confusion, disorientation, marked drowsiness, fever, severe headache, or a stiff neck. Sudden hallucinations in an older or physically unwell person also need prompt assessment.

Get urgent help after stopping heavy alcohol use or a sedative medicine if hallucinations occur with shaking, sweating, severe agitation, or seizures. Withdrawal can require monitored treatment.

Book a routine appointment if hallucinations are new, keep returning, cause distress, disturb sleep, or interfere with daily life. You should also arrange a review if they began after a medicine change or are occurring with changes in memory, mood, movement, vision, or hearing.

A healthcare professional will ask what you experienced, when it began, how long it lasted, and whether you knew it might not be real. It is helpful to explain which senses were involved and whether anything made the experience better or worse.

They may ask about sleep, recent illness, mood, stress, memory, alcohol or drug use, and prescribed or non-prescribed medicines. Honest information helps guide safe care and should be handled without judgment.

A physical examination may check your temperature, alertness, eyesight, hearing, movement, and nervous system. Depending on the circumstances, testing might include blood or urine tests, a medicine review, a hearing or eye assessment, brain imaging, or tests for seizures.

If you agree, information from someone who witnessed the episode may help, particularly if you were confused or cannot remember everything clearly.

Treatment depends on the cause rather than the hallucination alone. An infection, withdrawal state, sleep disorder, eyesight problem, neurological condition, or mental health condition may each need a different approach.

A clinician may adjust a contributing medicine, but you should not change or stop prescribed treatment on your own. Other care may include improving sleep, correcting vision or hearing problems, treating an underlying illness, talking therapy, or medication aimed at psychosis or another diagnosed condition.

Until you are assessed:

• Prioritise regular sleep and meals
• Avoid alcohol and recreational drugs
• Record when episodes happen and any medicine changes
• Stay with someone you trust if you feel unsafe
• Avoid driving or hazardous tasks during an episode

If you are supporting someone, remain calm and acknowledge that the experience feels real to them. You do not need to agree that it is happening. Focus on reassurance, reduce noise or stimulation, and seek help if safety is uncertain.

Brief hallucinations related to sleep may stop within seconds or minutes. Those caused by illness, medicines, substance use, or sensory loss may continue until the cause is addressed.

Some people have recurring hallucinations while remaining aware that the experiences are not real. Others may need ongoing support for a neurological or mental health condition. Early assessment can identify treatable causes and help reduce distress or safety risks.

Keeping a short record of timing, sleep, symptoms, and medicines can make patterns easier to recognise at follow-up.

Does hearing voices mean schizophrenia?

No. Hearing voices has many possible causes, including sleep-related experiences, medicines, substances, physical illness, sensory loss, and several mental health conditions. An assessment is needed to understand the context.

Can stress or anxiety cause hallucinations?

Severe stress, trauma, and prolonged sleep loss can affect perception. However, new hallucinations should not automatically be put down to anxiety, especially if they recur or occur with confusion or physical symptoms.

Should I challenge what I see or hear?

If you recognise the experience as a hallucination, moving to a well-lit, quiet place or checking with someone you trust may help. Do not take risks to prove whether something is real. Seek urgent help if the experience is threatening or affects safety.

Should I tell a healthcare professional about drug or alcohol use?

Yes. This information can be essential for safe treatment, especially because intoxication and withdrawal may require different care.