What Are the Different Types of Hallucinations?
A hallucination is something you see, hear, feel, smell, or taste that isn’t really there. Hallucinations can happen through any of the five senses, but the most common types are visual and auditory (hearing) hallucinations.
Auditory hallucinations can range from mild distortions to voices when nobody is speaking. The voices may be quiet or loud, friendly or intimidating.
Auditory hallucinations are the most common type that people with schizophrenia experience. Distortions in and intensity of auditory experiences such as listening to music are common among people taking hallucinogenic drugs.
Visual hallucinations can be mild distortions of what you see or visions of things that aren’t there. They can be pleasant or unpleasant and can shift quickly from one to the other, causing rapid mood changes.
Common visual hallucinations include:
- Unusually vivid colors
- Clear visual illusions
- New patterns within naturally occurring patterns, such as the veins on a leaf, or patterns superimposed onto objects
- Nonexistent objects or people
- Faces that look artificial or made of plastic, clay, or some other inanimate substance
- Halos around objects
- Peripheral vision anomalies
- Walls that look like they’re “breathing”
Visual hallucinations are a hallmark effect of hallucinogenic drugs such as LSD. The extent to which people experience hallucinations while under their influence varies.1
Some people see them consistently on low doses of a drug, whereas other people experience only a stimulant effect, even on high doses. This can change rapidly within the same drug experience. People who have never hallucinated before may suddenly find themselves in an alien, seemingly make-believe world.
Tactile hallucinations are physical sensations of something that is not there. Mild tactile hallucinations are common in people high on psychoactive drugs and are not always pleasurable or mild. All of these drugs are unpredictable and vary in effect from one person to another.1
Crystal meth is notorious for producing unpleasant tactile hallucinations. People who take meth often feel as if bugs are crawling over or under their skin. These tactile hallucinations can feel so real that people scratch or pick holes in their skin while trying to remove the nonexistent bugs. This can lead to sores, scabs, scars, and infections.2
Olfactory hallucinations involve smelling something that is not there. They can be associated with brain damage and epileptic seizures.
This kind of hallucination can be especially troubling, particularly if it overlaps with delusions. For a person who believes the house is on fire, for example, an olfactory hallucination of smoke would validate that belief.
Gustatory (taste) hallucinations are rare. Like olfactory hallucinations, they sometimes happen in conjunction with brain damage and seizures.
Like olfactory hallucinations, they can pose particular distress when coupled with delusions. For example, a taste hallucination would be extremely upsetting for someone with a delusion that they are being poisoned. They might perceive it as proof that the delusion is true.
Hypnagogic hallucinations happen in the stage between wakefulness and sleep. They’re very common, regardless of mental health status. They’re usually visual, unlike hallucinations associated with mental illnesses such as schizophrenia. In the absence of such conditions, people generally realize that they are hallucinations and not real.
Some conditions predispose people to hypnagogic hallucinations, such as:
- Clinical depression
- Bipolar disorder
- Postpartum psychosis
- Post-traumatic stress disorder (PTSD)
- Borderline personality disorder
In addition, some drugs such as amitriptyline that are used to treat mental conditions can increase hypnagogic hallucinations.
What Causes Hallucinations?
Hallucinations can happen under the influence of drugs, especially hallucinogenic or psychedelic substances such as LSD and magic mushrooms. Hallucinations can be a symptom of psychosis as well, such as in schizophrenia and bipolar disorder.
In addition, hallucinations can happen to almost anyone subjected to extreme physical or mental stress. Other possible causes include extreme sleep deprivation, migraines, epilepsy, and social isolation.
Treatment for hallucinations relies entirely on the condition causing them. Typically, a clinician will recommend a combination of medication and therapy, along with some strategies a person can use to deal with hallucinations.
Therapists usually encourage people to explore how they feel about the hallucinations and what they sense before, during, and after them. A clinician might recommend reading materials and websites to educate the person about the condition, possible causes, and treatments.
Medication and Other Treatments
Some medications can help eliminate or reduce the frequency of hallucinations. Others are prescribed to help calm the person so they can cope.
Research on drugs and treatments for hallucinations is ongoing. For example, the relatively new drug Nuplazid (pimavanserin) is the first approved for hallucinations associated with Parkinson’s disease.
Some research indicates that transcranial magnetic stimulation (TMS) might help reduce the frequency and severity of auditory hallucinations in some people with schizophrenia.
A person experiencing auditory hallucinations might benefit from:
- Humming or singing a familiar song (such as “Happy Birthday”) repetitively
- Ignoring the voices
- Listening to music
- Conversing with trusted friends or family
What can I expect in the long term?
Recovery from hallucinations depends on the cause. If you’re not sleeping enough or you’re drinking too much, these behaviors can be adjusted.
If your condition is caused by a mental illness, like schizophrenia, taking the right medications can improve your hallucinations significantly. By seeing a doctor immediately and following a treatment plan, you’re more likely to have a positive long-term outcome.