Sleep Hallucinations: Things That Go Bump In The Night

photo of a woman in bed experiencing hypnagogic hallucinations

Do strange images of geometric shapes, people or animals appear out of nowhere as you lie in bed at night? Perhaps you’ve heard voices or noises which can’t possibly be real?

If so, it could be that you’ve experienced what’s known as sleep hallucinations.

Despite leading to the occasional leap out of bed in sheer terror, they are usually harmless. And many people experience them at some point in their lives – including me.

My nocturnal flying geometric manifestations

As a child, multicolored geometric shapes would regularly swoop across my bedroom, just as I thought I was drifting off to sleep. I remember simultaneously 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 my mathematical manifestations.

Perhaps I should be grateful for my geeky hallucinations – especially compared to the disturbing experiences some people have.

What are sleep hallucinations?

Sleep hallucinations are imaginary experiences that happen during the transition between being awake and asleep, and can feel confusingly real.

They are also referred to as hypnagogic hallucinations if they occur while you’re falling asleep, or hypnopompic hallucinations if they happen while waking up.

The hallucinations are usually visual, such as seeing shapes or figures in the dark. But they can also involve your other senses.

The hallucinations can be vivid and frightening in some cases. If you see a giant creature in your room or hear a scary voice, it’s understandable that some people will jump out of bed and turn the light on to check what’s going on!

image explaining that hypagogic hallucinations occur while falling asleep and hypnopompic hallucinations while waking up

How many people have sleep hallucinations?

A commonly quoted statistic in medical articles comes from research conducted in 1996. The team interviewed 4972 people in the United Kingdom by telephone. They found that 37% had experienced hypnagogic hallucinations. And 12.5% had experienced hypnopompic hallucinations.

In 2000, another team of researchers surveyed 13,057 people and found that 38.7% had experienced hallucinations at some point during the day or night. 24.8% of the sample had experienced hallucinations at sleep onset, and 6.6% upon waking.

A sign of Narcolepsy

For some people, sleep hallucinations can be a sign of narcolepsy. Narcolepsy is a sleep disorder which involves sudden daytime episodes of:

  • Unexpectedly falling asleep
  • Sleep paralysis
  • Hypnagogic hallucinations

If you have these symptoms, it’s important to seek medical advice.


The main symptom is imagining events while falling asleep or waking up that are not real. Researchers believe that the most common type of hallucination is visual.

However, it’s possible to experience hallucinations that correspond to any of your senses:

  • Visual – such as geometric patterns, shapes or light flashing. Sometimes complex forms like animals or people.
  • Auditory – voices talking, phone or doorbell ringing, music, hissing, humming or whistling.
  • Olfactory – pleasant or unpleasant smells.
  • Tactile – insects crawling on the skin, rubbing, stroking, tapping or tickling sensations. Perhaps also feeling weightless, distortions in the body, flying.
image of a woman in bed with patterns and animal forms around her

Not the same as nightmares

Telling the difference between dreaming and hallucinating isn’t always obvious in the moment. But sleep hallucinations are not the same as nightmares.

When you wake up from a nightmare, you’ll know you were asleep (even if it takes a little while to come back to reality).

Sleep hallucinations, however, can feel like they are really happening. You know you’re awake, but you’re not convinced it’s merely your imagination playing tricks on you.

Coexisting with sleep paralysis

Sleep hallucinations sometimes happen during an episode of sleep paralysis.

During sleep paralysis, you might be unable to move your body in bed, which in itself is often frightening.

The hallucinations that accompany it can range from seeing a presence in the room to seeing and feeling a creature sitting on you.


The International Classification of Sleep Disorders manual suggests two causes related to brain function, though also states that more research is needed:

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

Health websites, such as, suggest that sleep hallucinations can be caused by other conditions, such as:

  • Sleep disorders like narcolepsy or sleep paralysis
  • A medical condition or medication use
  • A mental health disorder, such as schizophrenia
  • Substance abuse

Risk factors

According to the American Academy of Sleep Medicine, they are more common in children and young adults. Women might experience them slightly more often than men.

Some factors are thought to increase the likelihood or severity of the hallucinations, including:

  • Drug or alcohol use
  • Anxiety or stress
  • Mood disorders like bipolar disorder or depression
  • Insomnia
  • Epileptic seizures


Do you need to see a doctor?

If you’re experiencing anxiety or losing sleep because of regular sleep hallucinations, it’s a good idea to speak to a doctor or sleep specialist.

They would ask you about your hallucinations and look at your medical history and other factors like medication and lifestyle. They might decide that an overnight sleep study is needed to find out more.

They would also look at the possibility of another condition causing the episodes. And if they find one, give you the appropriate treatment.

What can you do to help reduce them?

Here are some ideas which might help keep the hallucinations at bay:

  • Get an adequate amount of sleep every night. Try to stick to a regular sleep schedule and don’t allow yourself to become sleep deprived.
  • Avoid recreational drugs.
  • 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 sounds that are not real, 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. 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 an activity you find 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, 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.

Your thoughts

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

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

1,172 thoughts on “Sleep Hallucinations: Things That Go Bump In The Night”

  1. I’m glad i found this article. i’ve been having different types of sleep hallucinations my whole life. I’m still young, 19, but i just woke up suddenly from a deep sleep and seen a crab walk across my pillow. yes, i’m very imaginative. but now i can’t go back to sleep. oh well, at least having some understanding will ease my anxiety

  2. Reading the article has given me a sense of comfort. I really thought I was going crazy. I believe I had this sleep disorder since I was a child. When I was a child I would see figures, but only a couple times out the years. Now I see things almost every night before I go to sleep. Figures like big spiders, people, or demonic things. No matter where I am or what room I’m in, it always comes. It keeps me up at night and it takes about a couple of hours before it goes away. It really scares my husband and I don’t know what to do.

  3. Wow thank you for this article. I have been noticing things at night in my room only and it has scared me and I did not know how to explain it without sounding crazy. I see on my walls and ceilings patterns and numbers in green color and it puts me in mind of a computer the old ones from the 80’s even after I wake up it is still there. I have seen dark shadows go across my celing and I have seen people never demonic except for one of them one night. I have what looks like being able to see thru walls there will be green leaves blowing in the wind and then early morning rain and daylight I can see through the wall just weird stuff. This started about a month ago I have also felt someone touch my side and sit on my bed.

  4. Could it ever be Paranormal / demonic? – I try to keep a balanced mind, skeptical but not closed, & 9x out 10 it will be medical, hallucinatory – But I’m also aware there are things that science cannot explain – Like why I experienced (unwanted & unexpected) death premonitions when people I’d known, but lost contact with, had been dying at that time; there’s some VERY weird stuff in this world, which don’t all fit into ‘normality’.

  5. Yaquelin Brambila

    I’m so happy to read this article! And to know that I’m not alone, for many years – and I’m talking about years – I have been seeing objects, objects that I’m not able to identify what they are. And they’re just floating in my room or in the hallways. It’s always when I’m asleep something makes me wake up and when I open my eyes there they are. I am used to them already but I always wonder what is it and why does my mind create this.

  6. For the last six months I’ve been seeing images of animals, dead people, family members, strange faces I have never seen. Sometimes when I’m awake its quite scary – don’t know what’s real or imaginary anymore. I think I need help.

    1. Hi Chris
      I imagine this must be very upsetting for you. It might be a good idea to talk to your doctor about what’s going on for, and how you’re feeling – especially if this is happening during the daytime. Hopefully, they will be able to help you in a way that’s positive for you.

  7. Hi, at childhood approx ~5 years I was seeing at night like a clock which spins around or moving left and right like coupe inches. If it was shadow on wall I was believing that it’s monsters but I never saw real vivid monsters… I never saw external things only things which was real but it was moving or spinning around. Is it hallucinations or delusions? Thanks for answer

  8. It’s been happening to me a lot recently. My experience has been a black shape almost like a bigger spider crawling up my wall and then disappearing as it reaches the ceiling. Always while I wake up in the night from being asleep. It’s never scared me just more of a what the hell moment and then curiosity. The last night I saw it, I got up in my bed and tried to follow it till it disappeared right above my head. It’s just so weird I wonder if now I’m subconsciously thinking about it and that’s why it keeps happening.

  9. Most times when I wake from a deeper sleep than normal or troubled sleep I see crawling spiders on my ceiling and walls.
    before sleep, as I close my eyes I get flashes of imagery usually motion images, and I see numbers, usually in the form of complex equations, almost like viewing a computer while it processes numbers, but now I’ve started to see numbers and letters on the ceiling when I wake, usually in a cipher style arrangement, or like watching matrix images that you see.
    is it possible that the imagery is what scares us most or what fascinates us most projected onto white surface upon waking or falling asleep, I ask because spiders are my biggest fear awake, and patterns in numbers is an obsession for me recently, specially palindromic numbers like 6556 or sets of double digits like 6565

  10. I’ve seen these odd mutant spiders on and off for about 7 years now, oddly enough I don’t find them as terrifying as you’d expect from a multi-eyed swarm of monstrosities with an odd number of legs

    Each the size of my fist on average and mottled grey and brown. Real arachnids give me the heebie-jeebies but these little eldritch abominations just inspire curiosity.

  11. I’ve been having this issue since I was 7. I always see ppl looking at me or creatures they’re weird demonic beings that I can’t describe due to me not knowing what it is. But after my stepfather terrified me at 8 with a werewolf costume I knew what that one who has always been there was. And then when I watched it another made sense and so on and so on. They all had characteristics since I can remember from the one behind my chair to the creepy animal monsters in my closet with glowing red eyes that I could see crawl along the floor and pop up next to my bed. And then they’d transfer into my dreams if I was terrified enough that night. How I’ve lived with it is very dim lights due to light bothering me while I sleep. And I always have to face the wall due to me being scared of it and not wanting to see it coming so I’d constantly hide in the corner.

  12. Wow! Thanks for the article. Glad to know I’m not alone here. The two images in the article are also very close to what I’ve seen. Not color but moving, blending images. I am 60 years old and have never experienced this before. The first time was only @ 3 months ago and I WAS under a lot of stress. In the corner of the wall and ceiling, above the door, I saw heavy and dark charcoal-drawn faces moving in and out of the crowd that could have been hundreds of people. The only word I can find to describe the feeling is pure anguish. It was if they were all being taken to the gas chambers at Auschwitz. None looked at me. No eye contact. I thought this was due to stress.

    Then, just two nights ago I saw (in the same place) what looked like leaves moving at night and lights (fire flies?) moving in and around them. I closed my eyes and when I opened them the moving leaves were now a thick school of fish swimming and swarming around each other. Not stressful at all. Just interesting. I closed my eyes again and went back to sleep.

  13. I have for years been waking and seeing people, (I could tell you exactly what they were wearing, a small boy sitting at the end, Marine in full dress uniform standing at attention, a mom, dad and baby all in Green Bay Packer sweatshirts, last night it was two dogs. I thought was going crazy as no one believed me. Your information was very helpful! Thank you!

    1. Wow lots of posts about seeing things, so let me get this straight. When you see things is it when you have woken up eyes open or are your eyes closed? Or both? This happened to me once. I woke up, eyes open and saw a spider, and then it disappeared.

  14. I keep a flashlight next to me in bed for when the hallucinations are particularly large or difficult to overlook. Pointing it at a specific object often makes it go away. Prior to that, I tried not to leave my bedroom because such images made it difficult to find my way back.

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