Hypnagogic Hallucinations Signs and Symptoms

A simple hypnagogic hallucinations definition is imagining something while you are falling asleep.
It can be an auditory, sensory, tactile or any other sensory experience. Whatever it is though, it’s not real and your brain is creating it.

Hypnopompic hallucinations are exactly the same thing, except that they occur while you are waking from sleep.
Both hypnagogic and hypnopompic hallucinations are usually quite vivid. Because they are so realistic, they can be overwhelmingly disturbing.

Especially if you end up with the pesky demon sitting on your chest kind of experience.

Hypnagogic hallucinations usually occur at the onset of sleep, either during daytime sleep episodes or at night.

It is occasions of seeing and hearing things in sleep. These dreams can be frightening and can often cause a sudden jerk and arousal just before sleep onset.

Hypnagogic hallucinations are dreams that break off on wakefulness, which can cause visual, auditory, or touchable sensations.

They occur between waking and sleeping, usually at the onset of sleep, and can also occur about 30 seconds after a cataleptic attack.

Hypnagogic hallucinations are a feature of narcolepsy. Sleep deprivation, medications, and irregular sleep schedules, all can predispose to happenings of this phenomenon.

How many people experience them?

sunset with statistic that one third of people experience hallucinationsThere hasn’t been much research done to find out how many people experience the phenomenon. But the following do show how common it might be:

  • There was a large telephone survey in the United Kingdom in 1996 of 4972 people. It was found that 37% experienced hypnagogic hallucinations twice a week or more. And 12.5% experienced hypnopompic hallucinations. It was more common amongst people with insomnia, excessive daytime sleepiness and mental illness.
  • A review of 35 different studies in 2011 found that 7.6% of people experience sleep paralysis in their lifetime. We’ll see later how sleep paralysis goes hand in hand with hypnagogic hallucinations.
  • In 2000 a survey of 13,000 people found that 38.7% experienced hallucinations. Though 27% were in the daytime. 2.7% of people had them once a week, with 2.4% more than once a week.
    So you can see that if you do experience hypnagogic and hypnopompic hallucinations, you are definitely not alone!

Symptoms of hypnagogic hallucinations

It’s possible to experience hallucinations that correspond to any of your senses. The following seem to be the most common. They can be experienced from between just a few seconds to a few minutes:

  • Visual – for example the geometric shapes in the picture at the top. But possibly also images of people or other complex shapes. People who have been doing repetitive tasks may also find they see after-images. Many computer gamers will know this very well.
  • Auditory – this can be simple sounds like hissing, humming or whistling. But it can also be more complex sounds like human voices. And it may also be extremely loud, such as with the sleep disorder exploding head syndrome.
  • Olfactory – perceiving smells which aren’t actually there. It can be pleasant smells or the kind of smell you definitely don’t want in bed.
  • Tactile – this can be disturbing such as feeling like there are insects or spiders crawling on the skin. Or it can be a strange rubbing, tapping or tickling sensation.

Furthermore there can be more complex hallucinations as felt in other sleep disorders. So for example with sleep paralysis, people may feel that they are unable to move.

And worse still, feel that there is a a burglar or intruder in the room with them.

It’s also very common to experience hypnic jerks when falling asleep. These can take many forms such as the sensation of falling.

Causes Of Hypnagogic Hallucination

There are several medical and psychiatric causes of hypnagogic hallucinations. Some of the common causes include the following:

Sleep Deprivation And/Or Exhaustion

Physical and emotional tiredness can induce hallucinations by blurring the line between sleep and wakefulness.


Prolonged or extreme stress can impede thought processes and trigger hallucinations.

Meditation And/Or Sensory Deprivation

When the brain lacks external stimulation to form perceptions, it may compensate by referencing the memory and form hallucinatory perceptions. This condition is commonly found in blind and deaf individuals.

Electrical Or Neurochemical Activity In The Brain

A hallucinatory sensation, usually involving touch called an aura, often appears before, and gives warning of, a migraine. Also, auras involving smell and touch (tactile) are known to warn of the onset of an epileptic attack.


Hallucinogenics such as LSD (lysergic acid diethylamide, or acid), psilocybin (4-phosphoryloxy-N, N-dimethyltryptamine, or mushrooms), ecstasy (3,4-methylenedioxymethamphetamine, or MDMA), and mescaline (3,4,5-trimethoxyphenethylamine, or peyote) trigger hallucinations.

Other drugs such as marijuana and PCP have hallucinatory effects. Certain prescription medications may also cause hallucinations. In addition, drug withdrawal may persuade tactile and visual hallucinations, as in an alcoholic suffering from delirium tremens (DTs).

Brain Damage Or Disease

Lesions or injuries to the brain may change brain function and produce hallucinations.

Mental illness

Up to 75% of schizophrenic patients admitted for treatment report hallucinations.

Hypnagogic Hallucinations Treatments

A quick medical evaluation should be sought, if someone starts to hallucinate and is disconnected from reality because many medical conditions that can cause hallucinations may quickly become emergencies. People who are hallucinating may become nervous, paranoid, and frightened and should not be left alone.

With regard to the underlying disorder the hallucinations are treated. Depending on the disorder, treatment may involve anticonvulsant, antidepressant medications, or antipsychotic; brain or ear surgery; psychotherapy; or therapy for drug dependence.

Hallucinations associated to normal sleeping and waking are not a cause for concern.

A psychologist or psychiatrist should treat hallucinations that are symptomatic of a mental illness such as schizophrenia.

Antipsychotic medication such as thioridazine (Mellaril), chlorpromazine (Thorazine), clozapine (Clozaril), haloperidol (Haldol), or risperidone (Risperdal) may be prescribed.

In many cases, medications can control chronic hallucinations caused by schizophrenia or some other mental illness.

Psychosocial therapy can be helpful in teaching the patient the coping skills to deal with them, if hallucinations persist. Hallucinations due to sleep deprivation or severe stress generally stop after the cause is removed.

Source & More Info: Sleep Disorders Guide and No Sleepless Nights



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