Types of Hallucinations

A hallucination is something that a person may think that they are experiencing that isn't really there. Hallucinations can happen through any of the five senses, creating a perception that they are real. Here we explore the different types of hallucinations based on each of the senses, also discussing their causes and treatment options.

5 Types of Hallucinations

We use our senses to decipher the world around us. What we see, hear, touch, taste, and feel impact how we perceive our environment and everything in it. Yet, sometimes these perceptions are false, appearing in the form of a hallucination. Here are five types of hallucinations based on their related senses.

Auditory Hallucinations

Auditory hallucinations involve hearing things that don't exist or hearing-related distortions. Examples include hearing voices when no one is speaking, hearing music when none is playing, or hearing a phone ring when no one is calling.

An estimated 10% to 15% of healthy individuals experience these types of hallucinations. Auditory hallucinations are also common in people with schizophrenia.

Other causes of auditory hallucinations include:

• Brain lesions
• Borderline personality disorder
• Hearing loss
• Post-traumatic stress disorder (PTSD)
• Sleep disorders
• Taking psychedelic drugs

Visual Hallucinations

Visual hallucinations involve distortions of what one sees or visions of things that aren't there. Seeing a person who isn't actually present in the room is an example of a visual hallucination. Animals, lights, and other objects can also be subjects of this hallucination type.

Visual hallucinations may look like:

• Colors that are unusually vivid
• New patterns within naturally occurring patterns, such as veins on a leaf or patterns superimposed onto objects
• Faces that appear to be artificial or made of plastic, clay, or some other inanimate substance
• Halos around objects
• Peripheral vision anomalies
• Walls that seem to be "breathing"

Visual distortions are often present with neurological disorders, such as Parkinson's disease and dementia with Lewy bodies, or mental disorders like schizophrenia. Some research has connected these hallucinations with atypical activity within nerve fibers that connect the thalamus and cortical regions of the brain.

This type of hallucination can also occur as a side effect of certain medications. This includes those designed to treat sleep disorders as well as medicines used to treat various types of infections (bacterial, fungal, and viral).

Tactile Hallucinations

Tactile hallucinations involve physical sensations on or within the body. With this type of hallucination, someone may falsely perceive that something is crawling on or stinging them, for example, or that their internal organs are shifting inside their body.

Roughly one in four people with schizophrenia experience tactile hallucinations. People with Alzheimer's disease, Parkinson's, and Lewy body dementia sometimes experience these hallucinations as well.

Tactile hallucinations can occur with recreational drugs like amphetamines, cocaine, and other narcotics. They're also a potential side effect of some prescription drugs, including those designed to treat Parkinson's, depression, high blood pressure, and epilepsy, along with prescription stimulants.

Olfactory Hallucinations

Also referred to as phantosmia, olfactory hallucinations involve smelling something that is not there. Someone with this hallucination type may perceive the smell of rotting garbage, burning rubber, smoke, chemicals, or some other item or substance that doesn't exist.

One study involving 2,500 individuals found that 4.2% of the subjects experienced olfactory hallucinations, with more than half (56%) experiencing them in combination with other types of hallucinations. It further noted that smell-related hallucinations were more common in subjects with anxiety or who had gone through stressful life events.

People with epilepsy or some level of brain damage may also have olfactory hallucinations. These hallucinations may even signal that a migraine is coming on.

Gustatory Hallucinations

Gustatory hallucinations involve false taste perceptions. Taste-related hallucinations include those described as bitter, metallic, rusty, or salty.

This type of hallucination is fairly prevalent in people with epilepsy. People with schizophrenia may also experience gustatory hallucinations, though less frequently than other hallucination types.

Like olfactory hallucinations, gustatory hallucinations can pose particular distress when coupled with delusions. For example, a taste hallucination may be extremely upsetting for someone with a delusion that they are being poisoned. They might perceive it as proof that the delusion is true.

Treatment for Hallucinations

Treating hallucinations requires identifying the condition causing them. Depending on the cause, a clinician may recommend therapy, medication, or another treatment option.

Therapy

Therapy can provide positive effects for people who experience hallucinations. The therapeutic approaches used for this purpose can vary.

Some therapies may involve increasing the patient's acceptance of their hallucinations. Others may utilize a mindfulness approach or seek to find the connection between the hallucinations experienced and the patient's personal history, relationships, or views of oneself.

Medications

Medications can help reduce the frequency of hallucinations. For example, selective serotonin reuptake inhibitors (SSRIs) can be helpful for visual hallucinations. Others may prescribed to help calm a person so they can cope with these false sight, taste, smell, touch, or hearing-related perceptions.

Research on drugs and treatments for hallucinations is ongoing with newer options being assessed. Progress is being made on this front, such as the drug Nuplazid (pimavanserin) being the first approved medication for hallucinations associated with Parkinson’s disease.

Other Treatments

Treatments that extend beyond therapy and medication may be options for certain hallucination types. Based on research, transcranial magnetic stimulation (TMS) might help reduce the frequency and severity of auditory hallucinations in some people with schizophrenia.

Depending on the cause, other treatment options may be available. These can include the use of various aids (such as using eyeglasses to improve vision and reduce visual hallucination frequency), surgery, and patient education.

Coping with Hallucinations

Certain strategies may also be employed to help patients cope with their hallucinations. As an example, a person experiencing auditory hallucinations in the form of voices might benefit from:

• Avoiding the use of alcohol and drugs
• Engaging in distraction techniques (listening to music, cooking, exercising, etc.)
• Getting enough sleep
• Joining a support group
• Taking control over the voices, choosing to ignore or confront them

A physician or mental health professional can help patients get to the bottom of these distressing occurrences and find a treatment that works for them.