Difference Between Hallucination and Delusion

Edited by Diffzy | Updated on: April 30, 2023


Difference Between Hallucination and Delusion

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In recent years, a variety of diseases have been identified that are linked to mental illnesses and people's impressions of society's standards or beliefs. These diseases or ailments have been extensively explored in recent years, and numerous causes and remedies have been discovered to some extent.

Hallucinations and delusions are two conditions that are similar to this one. While both of these are said to be based on one's brain's perception, they are vastly diverse and contain several distinctions. Let’s look at the differences.

Hallucination vs. Delusion 

The major distinction between hallucination and delusion is that the former refers to a state in which a person sees or believes in things that do not exist in reality or exist differently in reality. This could be caused to a variety of factors, including a lack of sleep. Experts, on the other hand, say the latter refers to a condition or circumstance in which a person assumes something is true despite all evidence pointing or indicating that it is not.

Difference Between Hallucination and Delusion in Tabular Form

Parameters of Comparison Hallucination Delusion
The meaning A person's state in which he believes certain sensory changes are occurring around him. A person's state in which he believes in a false world.
The causes This occurs as a result of a lack of sleep, the influence of alcohol or narcotics, and so on. It occurs as a result of some mental illnesses, such as depression.
The symptoms The individual who is afflicted may hear or see things. The individual who is afflicted will think something that is untrue and will appear strange to others.
The effects A person's senses. A person's beliefs.
The example Even when no one is walking, you can hear footfall. Believing that someone is chatting behind your back, even though he is not.
The treatment It can be treated solely with medicine. It will necessitate both medication and counselling (Difference Between Hallucination and Delusion (With Table), n.d.).

What is Hallucination?

The word "hallucination" derives from the Latin which means "mind wandering." Hallucinations are defined as "sensory experiences that are not induced by activation of the corresponding sensory organs" and "perception of a non-existent object or event."

In layman's terms, hallucinations occur when you hear, see, feel, smell, or even taste something that isn't there. The most frequent sort of hallucination is an auditory hallucination, which involves hearing voices or other noises that have no physical cause.

According to research, Hallucinations are common in people with psychiatric disorders such as schizophrenia and bipolar disorder; however, hallucinations are not limited to those with mental illnesses.

There are five different forms of hallucinations:

  • Auditory: Being able to hear voices or sounds that no one else can hear (a most common type of hallucination).
  • Visual: Seeing things that aren't real, such as people, colors, shapes, or objects (the second most common type of hallucination).
  • Tactile: Sensations (such as bugs crawling under your skin) or the sensation of being touched when you aren't.
  • Smelling something that has no physical source is referred to as olfactory (less common than visual and auditory hallucinations).
  • Gustatory: Having an unidentified flavor in your mouth (rarest type of hallucination).

Symptoms of Hallucination

Depending on the type of hallucination, it can cause a variety of symptoms, including:

  • Experiencing bodily sensations (such as a crawling feeling on the skin or movement)
  • Listening to noises (such as music, footsteps, or banging of doors)
  • Voices can be heard (can include positive or negative voices, such as a voice commanding you to harm yourself or others)
  • Seeing things, people, patterns, or lighting
  • Detecting a scent (can be pleasant or foul and in one or both nostrils)
  • Trying something new (often a metallic taste).

Diagnosis of Hallucination

For the diagnosis, your doctor will likely perform a physical exam and order a few tests after asking about your symptoms, medical history, and lifestyle habits to rule out medical or neurological reasons for your hallucinations. Now, A variety of diagnostic tests are available, including:

According to expert research, Tests to look for metabolic or toxic reasons in the blood are used often.

Also, an electroencephalogram (EEG) is used to check for seizures and abnormal electrical activity in the brain.

An MRI scan is used to look for structural brain problems such as a brain tumor or a stroke.

Causes of Hallucination

Most people link hallucinations with schizophrenia, a mental condition marked by abnormal thoughts and behaviors. They are, however, a potential symptom of bipolar disorder.

Both mania and despair can cause hallucinations in people with bipolar I disorder. Only during the depressive phase of bipolar II can hallucinations develop. The presence of hallucinations and/or delusions in bipolar disorder might lead to a diagnosis of bipolar disorder with psychotic characteristics.

Hallucinations can occur not just with mental health problems like schizophrenia and bipolar disorder, but also with the physical and psychological conditions listed below:

  • Use and/or withdrawal from alcohol or drugs
  • Hearing loss is caused by a disorder of the auditory nerve.
  • Dissociative identity disorder (DID) is a type of dissociative (DID)
  • Epilepsy
  • Glaucoma
  • Use of hallucinogens
  • Physiological conditions
  • Diseases of the middle or inner ear
  • MigraineNarcolepsy
  • Disorders of the nervous system
  • Diseases of the eyes
  • Post-traumatic stress disorder (PTSD) is a type of anxiety illness that occurs (PTSD)
  • Schizoaffective disorder (SAD) is a mental illness that affects people

Treatment of Hallucination

According to researchers, the type of hallucination, the underlying cause, and the overall health will all influence how you treat them. Your doctor will most probably propose a multidisciplinary strategy that involves medication, therapy, and social support in general.


Psychotherapy for hallucinations entails piquing the patient's interest in the specifics of their symptoms, giving psycho-education, examining "possible reasons" for the hallucinations, and normalizing the experience.

Self-Help Techniques

Patients who are suffering from auditory hallucinations can benefit from the following self-help strategies: 

  • Several times humming or singing a tune 
  • Ignoring the people's voices
  • Music is being played.
  • The act of reading (forward and backward)
  • Conversing with others.

Medication of Hallucination

Moreover, Antipsychotic drugs are most often beneficial in the treatment of hallucinations, either by eliminating or reducing their frequency or by having a soothing effect that makes them less distressing.

Nuplazid (pimavanserin) is the first medicine to be approved for the treatment of hallucinations associated with Parkinson's disease psychosis. Reassuring a loved one who is suffering hallucinations that treatment is accessible is a crucial part of assisting them. Here are a few more suggestions for assisting your loved one in dealing with hallucinations.

Misperceptions and hallucinations can be exacerbated by the surroundings; for example, a dimly lit room with a noisy, chaotic situation may enhance the likelihood of a hallucination. Although it's understandably terrifying and upsetting when a loved one has a hallucination, it's critical to respond calmly and supportively.

Depending on the degree of the hallucination, gently stroking or patting your loved one can act as a diversion and aid to minimise the hallucination. Conversation, music, or a change of location are all potential distractions.

Maintaining regular and consistent daily routines can reduce the likelihood of your loved one straying from reality and experiencing hallucinations. Consider keeping track of when you have hallucinations and under what circumstances they occur (Purse, 2020).

What is Delusion?

According to experts, Delusion is a strong belief that persists despite evidence to the contrary.

Delusion is frequently caused by a neurological issue or a mental condition. Delusion, on the other hand, is not linked to any one condition and has been observed as a symptom of a variety of medical and mental diseases. Delusion is a common symptom of psychotic illnesses such as schizophrenia, bipolar disorder, and paraphrenia.

Delusion is defined as "a delusional notion based on inaccurate inference regarding the external reality that is firmly maintained despite what almost everybody believes and despite what defines inconvertible and evident proof or evidence to the contrary," including the most recent version of the Diagnostic and Statistical Manual of Mental Disorders (DSM IV).

This definition excludes views that are widely held by members of the person's culture, such as those held as part of their faith (Mandal, n.d.).

Moreover, Delusions can be weird or non-bizarre. Bizarre delusions are the beliefs about events that will never occur, for example, the assumption that an individual has been abducted and even cloned by aliens.

Non-bizarre delusions, on the other hand, are beliefs that may or may not be true, such as the notion that one is being stalked, that someone loves them, or that one is being cheated on by a spouse.

Delusional disorder is a mental illness marked by non-bizarre delusions based on a misunderstanding of an event or perspective. People with delusional disorder sometimes have realistic delusions, such as the belief that they are being fooled or that they are being conspired against, but these are usually exaggerated or false.

Delusional disorder usually strikes in middle to later life, but it can strike at any moment. It also affects more women than men. Delusional disorder is often characterized by the individual's ability to socialize and operate regularly, as well as a lack of visible abnormal behavior, making it difficult to diagnose from the outside.

Delusional disorder differs from other psychotic diseases in which delusions are present, such as schizophrenia, because such conditions have other symptoms that can impede an individual's functioning. Begin with a low dose before gradually increasing it.

There are numerous sorts of delusions that can be experienced and are classified as delusional disorders. The major theme of the delusions is used to determine the type of delusional condition. The following are the various types:

  • Erotomanic- This form of delusion is the belief that someone is in love with the individual, usually someone famous or of higher social rank. For example, the person with this hallucination may believe that the famous person is sending them hidden messages on the TV show in which they star. With this form of hallucination, the individual may attempt to contact the person they believe loves them, which can lead to stalking behavior.
  • Grandiose- This form of hallucination is characterized by the assumption that an individual has an exaggerated sense of value, knowledge, fortune, ability, power, or celebrity despite the absence of proof. For example, someone suffering from grandiose delusions may believe they have made a significant discovery or that they have been sent to save the world by a religious institution.
  • Persecutory- According to research, the belief that the individual, or someone close to them, is being watched, stalked, drugged, cheated on, or mistreated is a sort of delusion. They may fear that someone is attempting to harm them or someone close to them, and as a result, they may file several complaints with the appropriate authorities.
  • Jealous- This sort of hallucination involves the perception that a love partner or spouse is unfaithful despite the lack of evidence. The individual may assume that their partner is meeting their hidden lover or sending secret messages to their lover when they are not present.

Diagnosis of Delusion

According to experts, if a person shows delusional symptoms, they might be evaluated to see if they have a delusional disorder. To begin, a doctor would most probably look into the patient's medical history and carry out a physical examination.

Also, some imaging tests, such as magnetic resonance imaging (MRI), can even be performed to rule out other possible causes of the symptoms, for example, Alzheimer's disease or epilepsy.

If the delusional disorder is still suspected, the person may be referred to a skilled psychiatrist, psychologist, or another health professional, who will make a diagnosis using interview techniques and assessment tools.

To analyse the symptoms against the diagnostic criteria, the professional will consult the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). The existence of non-bizarre hallucinations that have lasted for at least a month is required for a diagnosis of delusional disorder, according to the DSM-IV.

The delusions must not be accompanied by most types of hallucinations, indicating that the person has never satisfied the criteria for schizophrenia (Guy-Evans, 2021).

Main Differences Between Hallucination and Delusion In Points

  • A hallucination is a sensory experience—hearing, seeing, or touching something that does not exist in external, physical reality—that occurs in clinical terms (that is, outside the mind).
  • Delusions, on the other hand, are more conceptual. They refer to a person's broader ideas about reality or their situation, such as who they are or their life circumstances.
  • The state of hallucination is more of a thing that happens inside a person's head than it is something that happens in the outside world.
  • Delusion, on the other hand, is a little bit different. Rather than being anything tied to a person's senses, it relates to a person's conviction about a specific item. When a belief is held in a position that is utterly opposed to reality, it is referred to be a delusion (Difference Between Hallucination and Delusion (With Table), n.d.).
  • Hallucinations and delusions can occur in some mental illnesses, such as schizophrenia (“Delusion” vs. “Hallucination”: How To Truly Perceive The Difference Between Them, 2021).


Although hallucination and delusion both refer to a poor state of mind in a person, they do not necessarily indicate that these situations are the result of a mental disorder in that individual. These events can influence a person owing to a variety of variables such as alcohol, drugs, or depression, among others. Henceforth, now we got to know the differences between the two in detail.


  • “Delusion” vs. “Hallucination”: How To Truly Perceive The Difference Between Them. (2021, August 30). Retrieved from DICTIONARY.COM: https://www.dictionary.com/e/delusion-vs-hallucination/
  • Guy-Evans, O. (2021, November 27). What is a Delusion? Retrieved from SimplyPsychology: https://www.simplypsychology.org/definition-of-delusion.html
  • Mandal, D. A. (n.d.). What is Delusion? Retrieved from News Medical: https://www.news-medical.net/health/What-is-Delusion.aspx
  • Purse, M. (2020, July 21). What Are Hallucinations? Retrieved from verywellmind: https://www.verywellmind.com/what-are-hallucinations-378819


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"Difference Between Hallucination and Delusion." Diffzy.com, 2024. Mon. 15 Apr. 2024. <https://www.diffzy.com/article/difference-between-hallucination-and-delusion-465>.

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