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.
  • A couple of 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 for sleep 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.

638 CommentsLeave a comment

  • I too have frightening hypnopompic hallucinations of spiders when I wake during the night. I can completely eliminate the hallucinations if I wear an eye mask.

  • I see so many talk about this as something they are ‘suffering from’, which puzzles me as I have always thought about it as opposite. A cinema-like experience before drifting off to sleep. I have experienced Hypnagogic hallucinations for as long as I can remember and in fact until recently I thought that everyone experienced it upon falling asleep.
    I see vivid shapes, colours, weird animals, humans with monsterlike faces and half-men/half-beast creatures. It happens almost every night, and has for years (that’s why I thought it was normal:) I have however never been afraid (jolted a few times over snakes or the feeling of falling,) but I immediately understand that it is nothing to be afraid of. As a lover of fairytales and stories the hallucinations have instead been a wonderful and almost magical experience that I hope will never fade.

  • It’s awful I dont no if these are real or my medication. BIt for a fee months now the as been a little girl in my bedroom I wake and she’s there stood next to my tv close to my bed I ask her what she wants but she disapears. Tonight I had been asleep about 20mins and I suddenly woke and the was a tall man stood near my tv close to my bed I said hay what ya doing and he vanished. It this me is it real or is it my medication. Everything seems so real.

    • Hi Lucie
      Thanks for your comment. It depends what the medication is. You could mention this to your doctor and see if they can advise you if the mediation is causing it. If not, it could be a sleep hallucination you keep having, in which case, try the tips in the article to see if they help.

  • As a child, I would have rather frequent leg kicks while falling asleep. More recently, I’m over 50, I have been experiencing rather frequent and scary events while trying to fall asleep. I know I am awake still. I close my eyes and then it begins shortly thereafter. I see what appear to be, black ink spots taking different forms. I’m not sure what other colors are present. I also always hear a very loud swoosh sound that starts in my left ear and goes into my head or through my head to my other ear, not sure. It happens quickly out of nowhere and is very loud and disturbing. Last night, I opened my eyes to see if it would happen with them open, I don’t recall if it did, but I know I could not make out anything in the room. It was pitch black. Normally, I can make out some shadows of the door or some other objects. I closed my eyes again and it started again. I was trying to see if these ink-like blobs were forming any distinguishable images, but I don’t recall if they did. I can only say what I am experiencing is loud and frightening. I am on two different meds which I have been on for over a year, so I’m not certain if they would be contributing to this phenomena. I don’t like this at all.

  • I’m so glad I’m not crazy. Or maybe I am but at least not alone. These visuals at night have been happening to me as long as I can remember. I often see a human figure and it remains intact until I shoot up in bed and turn the light on and it is actually clothes on a chair. I see faces often usually in wall hangings which are usually flowers or decorative in nature..again turning the light on they go away. My ceiling fan above my bed scared the crap out of me the other night when the light cover came down off the fan as if it was a hidden camera and went back up into the fan as a sat up in bed. Crazy, right ? I could go on, there have been so many crazy things at night. I’m used to it by now but it still boggles my mind why it happens and what is going on. I have been on blood pressure medication for several years and I am wondering if this is a side effect.

  • This is a very refreshing read. I too have experienced visual and tactile episodes that will wake me up suddenly and have become frustrated with the situation due to the incident keeping me from falling back to sleep. I have experienced geometric shapes, feelings of insects, and appearances of people in my room. I never thought too much about it because I could usually talk myself down from discrediting a very real looking person in my room until I can realize that it is in fact just my chair or a coat hanger for example. What I can bring to this discussion about me to reassure others is that I’ve realized the two incidents that bring upon these episodes.
    I work as a firefighter working a 24 hour shift schedule in a high urban area that leads to very infrequent and broken sleep due to emergency responses, which leaves me exhausted at times. I encounter these episodes when either I am completely exhausted or when I am at the fire station. I very rarely get a good night sleep at the fire station and I never really experience these episodes when I am home having uninterrupted sleep. These hallucinations that wake me up at night that start very real and soon become realized for what they are happen for me only at the fire station where I very rarely have a perfect nights rest.
    This is a good read that makes me realize that it is not just myself that is dealing with this experience. I understand it for what it is and I have become better and quicker at identifying it when it is occurring, which in turn brings me back to sleep faster.

  • I have these and I kind of like it. When it happens, I know what I’m seeing isn’t real. So it’s rather enjoyable and a bit of a hoot. Sometimes I see (in the dark) what appears to be a swirling electrical field or something around my uncovered arm. If I reach out to touch it, it gets disturbed, like touching swirling water. Cool as hell. I was attributing it to one of my prescription medications perhaps. I am definitely not psychotic. My sleep patterns vary, and some nights I get more sleep than others. I don’t see anything in colors, always in a dark room. I get them both when I fall asleep and when waking in the middle of the night. I just go with it. If I start experiencing headaches out of the ordinary, I may get a brain scan to check for lesions. Otherwise, I’m going to chalk them up to meds and/or funky sleep patterns.

  • Thanks for this article. I’ve been suffering from this for years. For me it always happens as I’m drifting off to sleep. Usually I will jolt up out of bed in a panic because I can see spiders falling from the ceiling on to me. Sometimes it will be a snake somewhere in my bed that I’m frantically searching for until I realise what I’m doing and my husband asks me what am I doing?
    On 3 occasions it has been a person sitting next to my bed watching over me. That is scary and honestly until reading this I thought that it was a spirit, thankfully it has only ever happened a few times.
    I find that I don’t experience this happening as often as it used to, I’m 36 now and maybe only experience it once a month or less. It used to be very frequent in my teens and twenties.
    After reading through the responses I find it really interesting that so many of us all experience hallucinations of spiders, surely this isn’t a coincidence, I would love to find out more about it.
    I think you are right and that stress triggers it, last night I had one of the scary ones where I seen a man next to my bed. I had gone to bed upset and stressed after finding out my cousin is on life support and maybe that is why it happened. From now on i’am going to write down when it has happened and what is going on in my life that might have triggered it.

    • Your experiences are so similar to mine! I’m 22 and had these hallucinations for years, more often then not i will wake to see spiders all over my room or 1 giant spider on my bedroom floor, it scares the living day lights out of me but i have learnt to tell myself its not real and manage to calm down. I also had a snake one once, it was on my pillow and i chopped it in half for some reason and one half went under my pillow which caused me to frantically search my bed until i snapped out of it a few minutes later. The most frightening ones i have had was not recognizing my boyfriend and i would be terrified of him to the point i would be crying and thinking a dead person was walking around my room but after a minute or so i snap out of it and go back to sleep. My ex had a fright once when i woke him up kicking my legs and screaming as i thought a spider was lowering itself onto my face haha. I love reading other peoples experiences as i never really knew what they were. I have always been a sleep talker and used to rummage in my wardrobe when i was young whilst i was asleep but it just seems to have stemmed from that. I may do the same as yourself in regards to the journal, there must be a trigger for it, just a case of finding out what.

  • I’m glad it’s not just me! I always wondered if what I experience was a form of sleep paralysis, but I’ve always been able to move. They’re not too frequent thankfully, but I do have auditory and visual hallucinations sometimes. Strangely enough, only visual when I’m waking up and only auditory when I’m falling asleep.
    I wake up in the middle of the night sometimes and see things like an old man, a woman, a camera tripod once (no idea what that’s about). Once I thought I had a spider on my face and pulled a muscle leaping out of bed! When I’m falling asleep, it’s always the voice of someone I know and I can never remember what they’ve said.
    The visual ones have only ever happened when I’m stressed or upset, and the auditory ones happen at random and are more frequent. It all only started around a year ago. I’m just glad I’m not the only one!

  • I’m in a particularly stressful time in my life and I’ve started to have auditory hallucinations before falling asleep. Sometimes it’s a dog barking, a baby crying, a family members voice yelling my name. Random noises that scared me and I thought I was loosing my mind. This was really reassuring to read. Last night however after I layed down I had a very vivid dream that my boyfriend got up out of bed and had a conversation with me. I woke up right after that but was freaked out to find him asleep. The dream was so real I thought I was already awake. Maybe a lucid dream. I’m definitely going to try relaxing more before bed.

  • I have been having scary hallucinations as I wake up. It is nearly always near the window and uses the form of something that is already there, and then morphs into something else. Because I can see the shape in the darkness that is already there, it scares the crap out of me that I can then see it move/morph into something scary that is coming to get me. This makes me feel petrified, sometimes jumping out of bed with my heart hammering and I have to turn the light on to satisfy myself there is nothing bad there. It is horrible and obviously I don’t always look forward to falling asleep. I had them as a child too, and for much of my adult life. Because I can see the object already there, it scares me because I know I must be awake/semi awake and that’s why I feel so frightened when I see the cad shape move or morph because I know I’m awake, so it is worse than a nightmare. I also have nightmares and very vivid dreams that I always remember. Sleeping is exhausting sometimes!!!

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