Hypnagogic Hallucinations: Things That Go Bump In The Night

geometric shapes image demonstrating hypnagogic hallucinations

Have you ever seen something like this in the dark at night?

Have you ever switched off the bedside light, only to suddenly see strange shapes, animals or figures in the darkness? Perhaps you’ve heard voices or sounds which can’t possibly be real?

If so, it could be that you’ve experienced what’s known as a sleep hallucination, also sometimes referred to as hypnagogic hallucinations.

Many people experience hypnagogic hallucinations at some point in their lives, sometimes on a regular basis. And I’m no exception.

As a child I’d often see strange, multicolored geometric shapes in the darkness when trying to sleep. I used to lie there alternating between marveling at them and wishing them away so I could sleep in peace.

It doesn’t happen so often nowadays, but once in a while I’m still prone to these mathematical manifestations. Perhaps I should be grateful for my geeky hypnagogic hallucinations. Especially compared to the disturbing experiences that some people have.

So what exactly is this strange phenomenon and why does it happen? In this article I’ll be taking a closer look to help you understand what you’ve experienced yourself.


hypnagogic hallucinations occur when falling asleep, hypnopompic when waking upHypnagogic hallucinations are usually short-lasting experiences in which you might see, hear or feel something which isn’t real whilst transitioning from being awake to asleep.

It can be an auditory, sensory, tactile or any other sensory experience. Whatever form it takes though, it’s not real and is caused by your amazingly creative brain.

Hypnopompic hallucinations are exactly the same thing, except that they occur while you’re waking from sleep. For the sake of simplicity I’ll refer to the phenomenon as hypagogic hallucination throughout this article.

Both hypnagogic and hypnopompic hallucinations can be very vivid, so can be disturbing in some cases. Especially if you see creatures appearing in your room, voices saying unpleasant things or feeling something touch you.

The history

Hypnagogic hallucinations were first described in 1664 by the Dutch Physician Isbrand Van Diemerbroeck. He might not have called it by the name we know it as today, but he did describe a woman who appears to have experienced hypnagogic hallucinations.

How many people experience it?

up to one third of people experience hypnagogic hallucinations in their lifetimeThere hasn’t been much research done to find out how many people experience this. But the following surveys and research show how common it might be:

1. A telephone survey in the United Kingdom in 1996 of 4972 people found that 37% experienced hypnagogic hallucinations twice a week or more.

Furthermore, 12.5% experienced hypnopompic hallucinations. It was more common among people with insomnia, excessive daytime sleepiness and mental illness.

2. 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 often occurs alongside hypnagogic hallucinations.

3. 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 hallucinations, you’re definitely not alone!

Symptoms of hypnagogic hallucinations

It’s possible to experience hallucinations that correspond to any of your senses, though visual hallucinations are 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 above. But possibly also images of people, animals or other complex shapes.
  • Auditory – this can be simple sounds like hissing, humming or whistling. But it can also be more complex sounds like human voices. It may also be extremely loud, similar to the sleep disorder known as exploding head syndrome.
  • Olfactory – perceiving smells which aren’t actually there, either pleasant or unpleasant.
  • Tactile – this can be very disturbing, such as feeling insects or spiders crawling on the skin. It can also be a strange rubbing, stroking, tapping or tickling sensation.

Furthermore, there can be more complex hallucinations as part of sleep disorders such as sleep paralysis. You may feel unable to move your body, and perhaps see or sense a person or presence in the room.


The latest international classification of sleep disorders manual in 2014 presents the following 2 main causes, though does state more research is needed to confirm them:

  • An intrusion of dream imagery onto wakefulness.
  • A lack of stimulus leading to the visual cortex in the brain creating images.

The causes of sleep hallucinations may also be related to another illness or sleep disorder. For example, they’re often associated with these sleep disorders:

  • Narcolepsy.
  • Sleep paralysis.
  • Exploding head syndrome.
  • Excessive daytime sleepiness.
  • Sleep terrors.

They can also be associated with a mental illness such as Schizophrenia. Each of the above will have a particular way of explaining the causes that’s relevant to them.

In addition there are some things which might lead to an increase in frequency or intensity of hallucinations, including:

  • Stress.
  • Sleep deprivation or exhaustion.
  • Electrical activity in the brain.
  • Drugs – particularly illegal drugs such as hallucinogenics, ecstasy and marijuana. But also some medical drugs, including sleeping pills.
  • Brain damage or lesions.


relaxing can help reduce stress and prevent hallcuinationsA doctor would want to rule out any of the other illnesses or sleep disorders first, particularly narcolepsy and schizophrenia.

If you do have one of those, then your treatment would be tailored accordingly.

For example, Schizophrenia is usually treated with anti-psychotic medication. Narcolepsy will be treated with advice about lifestyle changes and possibly medication.

For most people, however, there’s no specific treatment for hypnagogic hallucinations and reassurance is the main need. It’s something which you just need to accept as a normal part of life.

Despite that, there are lifestyle choices you can make which may help. And the same applies to those who experience them as part of another sleep disorder. Here are some ideas which may help keep the hallucinations at bay:

  • Get an adequate amount of sleep every night, follow a stable sleep schedule and don’t allow yourself to become sleep deprived.
  • Avoid illegal drugs and check with a doctor if any medication you’re taking may be causing it.
  • Eat a healthy diet and drink plenty of water.
  • Try to reduce your stress levels.
  • Try using a soft night light in the bedroom. This might help fill the space that your brain uses as a blank canvas.
  • If you tend to hear things, perhaps listening to music or the radio at night will help.
  • If you find yourself focusing on visual hallucinations, try to re-focus your mind on something else. So for example, breathing exercises or muscle relaxation can keep your brain occupied.
  • If it’s overwhelming, turn on a light and get up for a while, do something relaxing and then try to sleep again after 10-15 minutes.
  • Several readers have said in the comments below that wearing a sleep mask helps them.

Generally though, you can see that hypnagogic and hypnopompic hallucinations are a normal part of life for many people. Once you’ve ruled out any serious illness or disorder, then you’re left to deal with the experience in two ways.

First, try to adapt your lifestyle to make sure you do everything possible to sleep well. Second, relax and try not to worry about things that go bump in the night.

If you do find yourself becoming overwhelmed by your experiences, it might help to talk to your doctor for some reassurance. You may also find it helpful to try some relaxation techniques which can help take your mind off any hallucinations.

Your thoughts

Do you ever experience hallucinations when falling asleep or waking up? What form do they take?

Do you find they get worse at certain points in your life, or if you do certain things? Have you found anything which helps prevent them?

Feel free to describe your experience in the comments below and share any ideas you have about dealing with them.

Please note that after years of responding to comments personally, I’ve now decided to leave this discussion entirely to readers.

I will still read your comment before publishing it, but would like to leave the fantastic discussion that has grown here over the years in your hands now.

676 CommentsLeave a comment

  • I’ve had these all my life and so have a few of my family members on one side. I have auditory hallucinations often, usually while falling asleep and I’ve had a few really vivid visual ones while waking up. I think I’ve had sleep paralysis, but it was never scary for me, I just knew that I couldn’t move yet, and then it was over, and I could. I’ve also had the geometric ones you described although mine have spinning pinwheels and sometime small pictures scattered throughout. There’s a lot of movement and colour. I call them my “circus shows” These have become very common since I started using a cpap. I never have hallucinations that combine senses, i.e., image with sound. My, non geometric, visual ones are usually people: a man who jumped from my mirror as a lion but stood up as a person; an old lady clutching her purse, leaning over me, smiling at me in anticipation( of what, I couldn’t tell you.); two small people with black hair and black eyes going through my sock drawer; etc. I never took note if they were in colour or black and white. The auditory ones can be the sound of someone calling my name or telling me something (sometimes I recognize the voice), someone yelling like they are falling from a cliff, a loud bang, a crowd (applauding, cheering, or just the din of many people talking), and sometimes it’s just bits and pieces of conversation, like someone tuning a radio. The only two that I found upsetting were the old lady (she felt like a ghost in the moment) and the one I had during postpartum depression when I woke up convinced that my infant would kill me if I went back to sleep. The last one was truly terrifying not only at the time ,because I really believed it, but also to this day, because if I had been the type of person to react quickly and not second guess myself, I could have harmed my son. Luckily, in the moment I remembered an article about a woman who had killed her children during an episode and I considered that I might be wrong. I woke my husband to watch the baby because I still believed he would harm us if we slept, and I took time to go clear my head and wake up fully. When I did, the whole idea that I could think like that felt completely ridiculous, except for the seriousness of it. It was a hallucination but I still feel guilty today that I ever even believed it for a minute. Perhaps the last one falls under delusion rather than hallucination or maybe it’s a version of the “scary presence in the room” feeling. I do think that postpartum depression is related to sleep deprivation, as I don’t have trouble recognizing reality in general (even during the other hallucinations, I’ve listed, I always knew I was seeing or hearing something that wasn’t real) and I was running on very little sleep at the time. My son was large (11lbs) and I was breastfeeding. He fed often. If I got one uninterrupted hour of sleep, it was a really big deal. I had a second son and my husband and I ensured that I got more sleep and I had no scary episodes. I’ve always had trouble with sleep. I fall asleep easily at any time, but I dream a lot and I wake as tired or more tired than when I went to sleep. I was assessed for narcolepsy but they found nothing in the sleep study. The CPAP is for UARS and I’ve only been using it for about a year. It helps a little as I have a little more energy, but as I said, the hallucinations are just different not decreased and I still dream a lot. Well, as Lo says, “I don’t know if this will help anyone but I thought I’d share. Peaceful rest to all.” You are not alone.

  • I see figures while sleeping, but I noticed that they are coming only when I over sleep or having stress and cant sleep or do not go into deeper sleep. I also noticed that if I took a sleeping pill and have a good night sleep, then I do not wake up seeing things.

    So my advise it to try and get a good consistent sleep cycle, and a deep sleep so that your mind is at rest and do not wake you up like a restless person. Its all about relaxing your mind.

  • I hallucinate bugs sometimes. When I’m trying to fall asleep and when I’m woken up after not being asleep for a very long time. They first started happening when I was a teenager. I would see a huge spider coming down one string of web from the ceiling right over my face. The first few times it happened I looked for the spider, couldn’t find it, and slept on the couch. I eventually realized that the spiders weren’t real. This usually happened when I stayed up really late and it was always the same thing: I spider dangling over my face. They stopped happening for a few years after I graduated but started again after I started spending nights at my boyfriend’s house, but this time I didn’t see spiders. One time it was bees, and one time it was a bug that I think I made up in my head. I’ve been experiencing it again recently. It’s been so long that I was thinking the bugs were real. Just a few days ago I was falling asleep and I saw I huge spider on my covers trying to creep under them. I tossed them off and jumped out of bed and fell to the floor. It was so loud it shook he house. My dogs started barking and it woke all my room mates. Just last night I saw a bunch of mosquitos carrying away my glasses from my bedside table (weirdest one yet). When I was younger it happened when I was sleep deprived, but I’m healthy and get a proper amount of sleep now, so I don’t know why these hallucinations would resurface. Really wish they weren’t always bugs. :/

  • I used to think the things I saw were ghosts when I was little and it scared me. I never get up, i dont know if i even can, i always stare until it disappears. Mine are monochromatic, never in colors. The worse one I had that caused me to look it up cause and discover this was I thought I had a death omen 4 years ago I woke, turned my head and saw 3 demon figures standing over me. HOLY CRAP I was terrified. Now I usually see spiders on the wall or ceiling, objects directly in my face that cause me the be startled and move my head like a chainsaw once, baseball bat last night. Sometimes i wake up to my name being said. I guess, explaining it, I do only move my head until the object is gone and then I turn over and go back to sleep. Doesn’t scare me anymore knowing that this is a common condition, just sometimes makes me jump. I only get 4 to 5 hours of sleep a night, I figure that may be the culprit.

  • I’ve suffered with sleep related hallucinations on and off for years, but in the past few months I have hallucinations upon waking several times a night. They are visual hallucinations, usually just shapes and patterns that I see in the walls, but are often accompanied by feelings of unease and I sometimes feel a very threatening presence. It’s not particularly nice, but I feel so used to it now that I’ve learnt to deal with it. However would it be advisable to see someone about it? I sometimes worry that my hallucinations are a sign of an underlying condition. Any advice would be greatly appreciated.

    • Hi Laura
      Thanks for your comment. I think if you feel like you’d like to speak to a professional about it, then by all means do so. If it only happens in the night, then it’s probably nothing to worry about. But if you feel that hearing that from a professional will reassure you, then go for it.

  • I’ve had this as long as I can remember. I believed for a long time I had seen a ghost but I’m pretty sure that was my mind playing tricks on me. I didn’t experience this for a long time but it has been more frequent recently. I’ll wake up or just as I’m falling asleep I’ll feel something or hear something then I’ll see lights, shapes, huge bugs, people or strange blob entities. Sometimes it takes a few seconds for what I’m seeing to go away and this used to make me blurt out “someone is in the house!” I’ve gotten pretty good at trying to let it fade away before I freak out but it’s still disturbing. Once I woke up and I saw an old lady leaning over my bed trying to grab me and I rolled over my husband and did a backwards somersault off the bed. Does anyone else have fibromyalgia or migraines? I wonder if this has any connection. It makes me feel crazy and embarrassed to talk about. The other night it felt as though someone sat down at the end of my bed and just stared at me. This is quite a haunting condition. As far as medication goes I can’t take much of any thing cause my fibro creates a sensitivity or intolerance to most drugs. I’m glad to know I’m probably not insane and others experiences these unpleasant nighttime visions. I get migraines on a regular basis and when I get an aura I notice my hallucinations increase. I don’t know if this will help anyone but I thought I’d share. Peaceful rest to all.

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