Hallucinations

Medically reviewed by:

Dr Sarah Marshall - Medical Officer

Updated: Aug 18, 2021

Next review: Aug 18, 2022

A hallucination is when someone has a sensory experience that doesn’t exist but is a creation of their own mind. Hallucinations can take various forms, all of which can be frightening for those experiencing them.

You can experience the following types of hallucinations:

Auditory hallucinations - hearing things that don’t exist (this is usually in the form of hearing voices, which can engage in both positive and negative conversations. These voices can often persuade someone to carry out certain actions, which can make these types of hallucinations a dangerous and upsetting experience.)
Visual hallucinations - seeing things that don’t exist
Olfactory hallucinations - smelling things that don’t exist
Gustatory hallucinations - tasting things that don’t exist
Tactile hallucinations - feeling things that don’t exist, as in someone touching you

You may also experience hypnagogic hallucinations when you are falling asleep, or hypnopompic hallucinations, when you are waking up, both of which are harmless unless experienced during other times of day. These are common in people who suffer from narcolepsy.

If you’ve been experiencing any of the hallucinations listed above, and you’re concerned about your symptoms, speak to a doctor as soon as you can.

You can talk to one of our online doctors from your own home, or wherever you feel safe, to discuss your hallucinations in a secure environment.

Whilst hallucinations can often affect people who are otherwise healthy, there can be many different causes, which can vary from mental health conditions, illness or disease to external factors.

Hallucinations can be caused by:

Migraines (many migraine sufferers see a multi-coloured light called an ‘aura’).
Sleep deprivation and sleep paralysis can sometimes lead to hallucinations.
Mental health conditions, such as schizophrenia, dementia or bipolar disorder
Neurological conditions, such as Parkinson’s disease or Alzheimer’s disease
Eye conditions, such as cataracts or retinal disease. Visual hallucinations can take the form of colours and patterns, or hallucinations of people or objects, and are common in people with visual impairments.
The use of, or withdrawal from, illegal drugs or excessive alcohol consumption (some drugs, such as LSD or ecstasy, can create hallucinations that are usually visual but can take any form. Long-term drug use can contribute to the development of mental health conditions, like schizophrenia or psychosis, whilst heavy alcohol consumption has been linked to psychosis and dementia.)
In older people, hallucinations can be caused by other illnesses such as infections, causing delirium
In children, hallucinations can occur if they are unwell with a very high fever

This list is not exhaustive – there are many different causes of hallucinations. If you’re experiencing any symptoms, speak to one of our doctors at a time that suits you today.

If you suspect that your hallucinations are induced by substance abuse, it’s advised you see a doctor as soon as you can to discuss changes you can make to your lifestyle.

When you’re experiencing hallucinations, make sure you are in the company of someone you trust and feel safe with.

Some hallucinations, like visual hallucinations in the form of hearing voices, can make the person experiencing them feel scared, and sometimes behave erratically.

It’s important to stay calm if someone you know is experiencing this and contact a doctor to assess possible treatments. If their behaviour becomes harmful, call 999 as soon as possible.

If you or someone in your family are experiencing hallucinations of any kind, you should discuss them with a doctor as soon as possible to determine the right next steps for you.

Dr Sarah Marshall - Medical Officer

What are hallucinations?

What causes hallucinations?

What should you do if you experience hallucinations?