Hallucination – Types, Causes, And Treatments.

hallucination is a sensation or sensory perception that a person experiences in the absence of a relevant external stimulus, that is, a person experiences something that does not really exist (except in his mind), it can occur in any sensory modality: visual, auditory, olfactory , gustatory, tactile …

They can often be meaningful to the person experiencing them, many times the voices are those of someone they know and tend to get worse when the person is alone.

Hallucinations are a symptom of a medical (eg, epilepsy ), neurological, or mental disorder. Hallucinations may be present in any of the following mental disorders: psychotic disorders (including schizophrenia , schizoaffective disorder , schizophreniform disorder), bipolar disorder , major depression with psychotic, features delirium  or dementia. 

Types of hallucinations

There are five types of hallucinations, including:


This is the most common type of hallucination, you may hear voices or sounds that no one else can, it refers to the perception of non-existent sounds. In schizophrenia, patients hear voices talking to them, but hallucinations can also take the form of whistling. The voices can be saying complementary or critical words to them, they can form a continuous comment on the actions of the person.

Auditory hallucination is also a well recognized feature of bipolar disorder and dementia , although it can occur in the absence of mental health conditions, it can be extremely distressing, although some people can learn to live with voices, especially if the words they hear are Neutral or complementary rather than negative, it also often occurs as a result of grief, which can lead the person to believe that they can hear the voice of a loved one.


Here, a person sees something that does not exist or sees something that does exist but sees it incorrectly. Various conditions can cause visual hallucinations such as dementia, migraines, and drug or alcohol addiction . This is the second most common type of hallucination.

Simple visuals

Also known as unformed and elemental visual hallucinations, these terms refer to lights, colors, geometric shapes, and indiscreet objects.

Complex visuals

They are also known as visual hallucinations formed, they are clear and realistic images or scenes, such as people, animals, objects, among others …


You can feel sensations or feel that they are touching you when they are not, this can include a feeling of errors that are crawling throughout your body. For example, you may feel insects crawl on your skin or your internal organs are moving or the imaginary touch of someone’s hands on your body. These hallucinations rarely occur in bipolar disorder .


You smell something that no one else can and that doesn’t have a physical source, you may smell something unpleasant when you wake up in the middle of the night, or you feel like your body smells bad when you don’t. This type of hallucination can also include aromas that are pleasant to you, such as the smell of flowers.


They are similar to olfactory hallucinations, but involve your sense of taste rather than smell, these tastes are often strange or unpleasant. Taste hallucinations (sometimes with a metallic taste) are a relatively common symptom for people with epilepsy . This is the rarest type of hallucination.

Causes of a hallucination

Hallucinations can be caused by a number of factors.

Hypnagogic hallucination

These occur just before falling asleep and affect a high proportion of the population, can last from seconds to minutes, the subject generally remains aware of the true nature of the images. These can be associated with narcolepsy and are sometimes associated with brain stem abnormalities, but this is rare. Read more information about: Hypnagogic hallucination. (Required item)


More than 70% of people with this disease have visual hallucinations, and 60% to 90% hear voices, but some can also smell and taste things that are not there. Complete content on: Schizophrenia.

Parkinson’s disease

Up to half of the people with this condition sometimes see things that are not there. The Parkinson ‘s disease is related dementia symptoms similar hallucinatory and appear overnight anywhere in the visual field, and are rarely polymodal. The transition to hallucination can begin with illusions where sensory perception is severely distorted, but no novel sensory information is present. These usually last several minutes, during which the subject may be conscious and normal or sleepy / inaccessible. Learn more about: Parkinson’s disease.

Charles Bonnet Síndrome

It is the name given to the visual hallucinations experienced by a person with partial or severe visual impairment, which can occur at any time and can distress people of any age, since initially they cannot realize that they are suffering from hallucinations, they may fear initially for his own mental health. Learn more about: Charles Bonnet syndrome. (Required item)


Visual hallucinations occur due to focal seizures that differ depending on the region of the brain where the seizure occurs.

Temporal lobe seizures, on the other hand, can produce complex visual hallucinations of people, scenes, animals, and more, as well as distortions of visual perception. Complex hallucinations may appear real or unreal, may or may not be distorted with respect to size, and may appear disturbing or personable, among other variables. If you want to know more, click here on Epilepsy.

Drug-induced hallucination

They are caused by the use of psychoactive substances and certain stimulants, which are known to cause visual and auditory hallucinations. Some psychedelics such as lysergic acid diethylamide (LSD) and psilocybin can cause hallucinations that range from a mild to severe spectrum.

How are hallucinations diagnosed?

The best thing to do is to call your doctor immediately if you suspect that your perceptions are not real, your doctor will ask about your symptoms and perform a physical exam, additional tests may include a blood or urine test and perhaps a brain scan.

If you know someone who is hallucinating, do not leave them alone, fear and paranoia caused by hallucinations can lead to dangerous actions or behaviors, stay with the person at all times and go with them to the doctor for emotional support, it can also help to answer questions about your symptoms and how often they occur.

How are hallucinations treated?

Your doctor will be able to recommend the best form of treatment once he finds out what is causing your hallucinations.


Treatment for a hallucination will depend entirely on its underlying cause. For example, if you are hallucinating due to severe alcohol withdrawal, your doctor may prescribe medications that slow down your nervous system. However, if hallucinations are caused by Parkinson’s disease in a person with dementia, this same type of medication may not be beneficial, an accurate diagnosis is very important to treat the condition effectively.

psychological counseling

Counseling can also be part of your treatment plan, this is particularly true if the underlying cause of your hallucinations is a mental health condition. Talking to a psychologist can help you better understand what is happening to you, it can also help you develop coping strategies, especially when you feel scared or paranoid.

Georgia Tarrant
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Hello, how are you? My name is Georgia Tarrant, and I am a clinical psychologist. In everyday life, professional obligations seem to predominate over our personal life. It's as if work takes up more and more of the time we'd love to devote to our love life, our family, or even a moment of leisure.