10 Types of Hallucinations: Characteristics and Possible Causes
When people talk about hallucinations, it’s common for them to panic. Many people worry when they hear this term because we often associate it with madness. Before we get started, it’s important to clarify that there are different types of hallucinations. However, in all of them, the people affected experience a detachment from reality.
Generally speaking, we can define hallucinations as sensitive responses to non-existent stimuli from the environment. This is the case with auditory hallucinations, where people hear voices or sounds that no person, animal, or object has made. The reason for this is an alteration on a neurological level.
There may be different reasons for such alteration to develop, similar to how it is in an extensive variety of hallucinations. In this article, we review 10 of the most common types and take a look at where they came from.
Causes of hallucinations
Regarding the diverse causes that can cause hallucinations, we have two main categories: organic (by some kind of neurological disorder) and those induced by substance consumption.
Caused by mental illness
There are several neurological disorders that can cause some kinds of hallucinations. Below, we review a list with the most common characteristics, according to the DSM-V Manual.
- Schizophrenia: This psychological disorder is the most closely associated with hallucinations. In this case, the person needs psychiatric treatment, which includes a pharmaceutical prescription.
- Dementia: The cognitive deterioration aspect during dementia can give way to visual and auditory types of hallucinations.
- Alzheimer’s disease: In this disorder, memory loss can cause gaps of information that are then substituted for false memories. Also, the patient could end up believing that they’re living in a different period of their life.
Other mental illnesses can also cause hallucinations, like Wernicke-Korsakoff syndrome, Parkinson’s disease, bipolar disorder, temporal lobe epilepsy, and even brain tumors.
By substance consumption
Regarding hallucinations induced by substances, consuming determined pharmaceuticals and drugs can give way to the issue. Some of the substances that induce hallucinations are the following:
- Alcoholic drinks: Consuming alcohol alters the central nervous system, which can cause visual and auditory hallucinations. Someone would have to drink an excessive amount for hallucinations to appear.
- Cannabis: Marijuana consumers also experience alterations in their central nervous system. Similarly, the cognitive deterioration that continuous consumption of this drug causes can develop into neurological disorders.
- Amphetamines: This kind of drug can cause manic reactions and episodes of psychosis. For that reason, it’s important to visit a doctor so that they can prescribe the correct dosage.
Other drugs like LSD can also cause visual and auditory hallucinations. In fact, some people even experience false sensations in their bodies.
Types of hallucinations
Now let’s take a look at a list of the 10 most common types of hallucinations. From there, we can identify which are the main characteristics.
So, to do this we’ll also take a look at the hallucinations we’ve mentioned above.
1. Visual hallucinations
This type of hallucination is the most well-known and most common; it’s about seeing things that aren’t really there.
This is the case with schizophrenia. The person can even establish an intimate bond with their hallucinations. Also, it may happen that the person sees themself that way, which is known as autoscopia.
2. Auditory hallucinations
These are also the most well-known and go hand-in-hand with visual hallucinations. However, they do sometimes occur by themselves.
For example, hearing voices as if a third person was talking. In these cases, the voices usually give opinions or instructions to those that hear them.
3. Gustatory hallucinations
Gustatory hallucinations (hallucinations with taste) are some of the least spoken about. The reason for this is, in comparison to the visual and auditory types, they aren’t that common. Above all, this phenomenon occurs during depressive states.
4. Olfactory hallucinations
Similar to the previous kind, this type of hallucination is uncommon. Olfactory hallucinations cause the person to experience the presence of smells that aren’t in the environment.
Also, they usually appear after drug consumption or as a result of strong migraines.
5. Somatic hallucinations
During these types of hallucinations, people usually have unrealistic perceptions of their organs. For example, they may feel like their lungs or heart are made of a metallic material, whilst others may feel like they’re missing parts of their body.
6. Tactile hallucinations
This is when someone has the sensation that something cold or hot is in contact with their skin, but, in reality, there’s nothing there.
In any case, there are two types: thermic (feeling cold or hot) and hydric (sensation of humidity). There’s also the kind where they experience pins and needles, known as paresthesia.
7. Kinesic hallucinations
Also known as kinesthetic hallucinations, this is where the person experiences sensations in respect to the movement of their body, In these cases, they tend to experience the realistic sensation that some part of their body is moving when it isn’t.
When we talk of pseudo-hallucinations, we’re referring to those of any kind where we can recognize as a distortion of reality. By this, we mean when a person is conscious that what they’re seeing, hearing, or feeling isn’t real.
9. Hypnagogic hallucinations
In this case, the person doesn’t necessarily have any kind of disorder nor are they necessarily under the effects of a substance. Hypnagogic hallucinations happen during the process of falling asleep.
When a person is passing from consciousness to sleep, they could experience visual, auditory, or tactile hallucinations.
10. Functional hallucinations
These happen when a perceived stimulus from any of the sensory channels causes a different response to what it should. For example, a person could hear traffic noises (a real stimulus) but at the same time, they hear voices speaking to them (a hallucination).
Is it dangerous to have these types of hallucinations?
Many people understand hallucinations to be dangerous. But, in reality, they’re a lot more common than you may have realized.
In fact, at some point, we’ll all experience a hallucination of some kind. For example, when we’re about to fall asleep, we may experience hypnagogic hallucinations, without it being a danger.
It’s important to be alert when these happen without any apparent reason, and when they’re intense and happen frequently. Alternatively, we can understand them as natural responses to certain psychiatric processes of the body.
All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.
- American Psychiatric Association (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Washington, DC
- Campero-Encinas, Daniela, Henry Campos-Lagrava, and Marcela Campero Encinas. “Esquizofrenia: La Complejidad de Una Enfermedad Desoladora.” Revista Científica Ciencia Médica 12.2 (2009): 32–37. Print.
- Acevedo-González, Juan Carlos, and María Lucía Salamanca-Ternera. “Semiología de Las Alucinaciones En Tumores Del Sistema Nervioso Central.” Universitas Medica 61.4 (2020): 55–65. Universitas Medica. Web.
- Álvarez, José et al. “Las Alucinaciones: Historia y Clínica.” Frenia. Revista de Historia de la Psiquiatría 1.1 (2001): 65-96–96. Print.
- García Montes, José M., and Marino Pérez Álvarez. “La Visión Skinneriana Sobre Las Alucinaciones. Vigencia y Revisión.” Psychology, Society, & Education 3.1 (2017): 15. Psychology, Society, & Education. Web.