Hallucinations are the perception of a nonexistent object or event and sensory experiences that are not caused by stimulation of the relevant sensory organs. The word "hallucination" comes from Latin and means "to wander mentally."
In layman's terms, hallucinations involve hearing, seeing, feeling, smelling, or even tasting things that are not real. Auditory hallucinations, which involve hearing voices or other sounds that have no physical source, are the most common type.
Hallucinations occur frequently in people with psychiatric conditions, including schizophrenia and bipolar disorder, however, you don’t necessarily need to have a mental illness to experience hallucinations. No matter what is causing hallucinations, they should be taken seriously.
There are five types of hallucinations, including:
Auditory hallucinations: Hearing voices or sounds that no one else can (most common type of hallucination)
Visual hallucinations: Seeing people, colors, shapes, or items that aren't real (second most common type of hallucination)
Tactile hallucinations: Feeling sensations (like bugs crawling under your skin) or as if you're being touched when you're not
Olfactory hallucinations: Smelling something that has no physical source (less common than visual and auditory hallucinations)
Gustatory hallucinations: Having a taste in your mouth that has no source (rarest type of hallucination)
Presence hallucinations: A sensation that someone is nearby or in the room with you when there isn't anyone there
Proprioceptive hallucinations: The feeling that your body is moving or that your limbs are separate from your body, when neither of these things are happening
Some people experience hallucinations at night or in the morning. These types of hallucinations include:
Hypnopompic: Hallucinations that take place as you're waking up from sleep
Hypnagogic: Hallucinations that take place as you're falling asleep
A hallucination is when your senses are perceiving something that isn't happening in reality (i.e., you see and hear a person in the room who's not really there). A delusion, on the other hand, is the belief that something is happening, for which there is no evidence (i.e., you believe that the government is controlling you through your TV).
Hallucinations can have a range of symptoms, depending on the type, including:
Feeling sensations in the body (such as a crawling feeling on the skin or movement)
Hearing sounds (such as music, footsteps, or banging of doors)
Hearing voices (can include positive or negative voices, such as a voice commanding you to harm yourself or others)
Seeing objects, beings, or patterns or lights
Smelling an odor (can be pleasant or foul and in one or both nostrils)
Tasting something (often a metallic taste)
You see someone in your bedroom and you hear them speaking to you (visual and auditory hallucination)
You see flashing lights outside of your window, but no one else sees them (visual hallucination)
After asking about your symptoms, medical history, and lifestyle habits, your health provider will likely do a physical exam and order a few tests to try and rule out medical or neurological causes of your hallucinations. Diagnostic tests may include:
Blood tests to check for metabolic or toxic causes
Electroencephalogram (EEG) to check for abnormal electrical activity in your brain and to check for seizures
Magnetic resonance imaging (MRI) to look for structural brain issues such as a brain tumor or stroke
Unfortunately, studies show that people underreport hallucinations. When talking to a doctor, it’s important to be honest about the duration and frequency as well as the specific symptoms associated with your hallucinations.
Hallucinations are most often associated with schizophrenia, a mental illness characterized by disordered thoughts and behaviors. However, they are also a possible characteristic of bipolar disorder.
With bipolar I disorder, hallucinations are possible both with mania and depression. In bipolar II, hallucinations may occur only during the depressive phase. Bipolar disorder that presents with hallucinations and/or delusions can also lead to a diagnosis of bipolar disorder with psychotic features.
Not only do hallucinations occur with mental health conditions like schizophrenia and bipolar disorder, but they can also occur with the following physical and psychological conditions as well:
Alcohol or drug use and/or withdrawal
Auditory nerve disease
Dissociative identity disorder (DID)
Epilepsy
Glaucoma
Hallucinogen use
Metabolic conditions
Middle or inner ear diseases
Migraine
Narcolepsy
Neurologic disorders
Ophthalmic diseases
Post-traumatic stress disorder (PTSD)
Schizoaffective disorder
Sleep deprivation
Stroke
The treatment of hallucinations will depend on the type of hallucination, the underlying cause, and your overall health. In general, however, your doctor will likely recommend a multidisciplinary approach that includes medication, therapy, and social support.
Psychotherapy for hallucinations involves engaging the patient to be curious around the details of the symptoms, providing psycho-education, exploring "plausible reasons" for the hallucinations and normalizing the experience.
The following self-help strategies can help patients cope with auditory hallucinations:
Exercise
Humming or singing a song several times (like "Happy Birthday")
Ignoring the voices
Listening to music
Reading (forward and backward)
Talking with others
Antipsychotic medications often are effective for treating hallucinations, either by eliminating or reducing the frequency with which they occur or by having a calming effect that makes them less distressing.
Nuplazid (pimavanserin) is the first drug approved to treat hallucinations associated with psychosis experienced with Parkinson’s disease.
Repetitive transcranial magnetic stimulation (rTMS), a relatively non-invasive procedure that involves placing a small magnetic device directly on the skull, has some preliminary evidence that it may be able to reduce the frequency and severity of auditory hallucinations in some people with schizophrenia.
An important aspect of helping a loved one who is experiencing hallucinations is reassuring them that treatment is available. Here are a few more practical steps for helping your loved one cope with hallucinations.
The environment can play an important role in misperceptions and worsening of hallucinations; for example, a poorly lit room and loud, chaotic setting may increase the likelihood of a hallucination.
Although it can be frightening and uncomfortable when a loved one experiences a hallucination, it’s important to do your best to respond in a calm, supportive manner. For example, you might say “I know this is scary for you” or “Don’t worry; I’m here.”
Depending on the severity of the hallucination, gently touching or patting your loved one may help serve as a distraction and reduce the hallucination. Other possible distractions include conversation, music, or a move to another room.
While you don’t want to upset your loved one or engage in an argument, you do want to be honest and assure them that you're not dismissing their concerns. If they ask: "Did you hear that?" Consider saying: "I know you heard something, but I didn’t hear it."
Keeping normal and reliable day-to-day routines can make it less likely that your loved one will stray from reality and experience hallucinations. Consider keeping a record of when hallucinations occur and under what circumstances.