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Parasomnias: 6 Strange, Sometimes Creepy Sleep Phenomena

These sleep disorders range from common occurrences to the truly bizarre.

"Parasomnias" is a term that covers a range of sleep disorders and disturbances, from common occurrences like sleepwalking to the truly bizarre, like "exploding head syndrome." If you experience any of these parasomnias, here are a few things you can do about them. (If these symptoms persist, talk to your doctor about getting a sleep study.)

1. Sleepwalking (somnambulism)

If you’ve ever woken up and found yourself outside your bed, with no idea how you got there, you may have experienced somnambulism, more commonly known as sleepwalking. You may even have woken up to find yourself looking at a half-drunk carton of orange juice, in the middle of texting your mom, or even walking outside in total darkness. That’s why sleepwalking isn’t just spooky for onlookers; it can actually be dangerous!

In fact, more than half of adult sleepwalkers have exhibited violent behaviors while sleepwalking. Seventeen percent have even ended up with enough injury to need medical attention, like one patient who jumped out of a third-floor window while totally asleep. The puzzling thing is that most sleepwalkers don't feel pain while sleepwalking, even if they're already in harm’s way.

What to do about it: If you see someone sleepwalking, gently guide them back to bed. If sleepwalking happens often to you, talk to your doctor about reviewing your medications, or possibly getting a sleep study. In the meantime, lock the front door, hide your keys, and put away anything else that could pose a danger to you and those around you.

Perhaps surprisingly, sleepwalking can be triggered by strong positive emotions. That doesn’t mean you should avoid things that bring you joy, but consider meditation or a wind-down period before bed to help you reach a state of emotional balance before you head off to dreamland.

2. Sleep-related eating disorder

Closely related to sleepwalking is sleep-eating, where someone involuntarily eats food while sleepwalking.

Sleep-eaters often also have insomnia and sleepiness during the day. But it's possible that some of them have more awareness during sleep-eating episodes than regular sleepwalkers. This can lead to significant weight gain because those who have a sleep-related eating disorder cannot control their food intake during the night.

What to do about it: Avoiding alcohol and drugs, limiting stress, and keeping a regular sleep-wake schedule can help.

3. REM-behavior sleep disorder (RBD)

Here’s a disorder that often is disguised as sleepwalking: REM-behavior sleep disorder.

One difference between RBD and sleepwalking is that RBD involves acting out dreams. This happens during REM sleep, in the second half of the night, whereas sleepwalking usually happens during deep sleep, which you get in the first half of the night.

For the most part, sleepwalkers have calm and neutral behaviors. But during an RBD episode, the sleeper is dreaming and acting out whatever is happening in their dream—usually an action like fighting or running, though sometimes it can also be a sophisticated behavior like playing the piano.

Usually, your brain "turns off" your muscles (something called "REM atonia") so you don’t act out your dreams. With RBD, this safety mechanism fails and the dream spills over into the body, playing it like a puppet.

What to do about it: Of course, safety is the most important concern with RBD. Many patients aren’t aware that they’re acting out their dreams until their bed partner ends up with bruises or they find themselves aggravating the cat. A sleep neurologist can help you to manage your symptoms.

4. Sleep terrors (a.k.a. night terrors) and nightmares

Sleep terrors seem, well, terrifying. You might burst out of bed, screaming and inconsolable for a few seconds or even minutes.

It’s important to note that "sleep terrors" and "nightmares" are very different. Nightmares are dreams that are disturbing, sometimes scary enough to wake us up in a panic, and might even affect our mood the next day. These typically happen in the second half of the night because dreaming happens largely during REM sleep.

Sleep terrors, in contrast, happen during deep sleep in the first half of the night, and there are no dreams involved. Someone in the middle of a sleep terror episode is not really awake—they’re disoriented, terrified, and can’t coherently talk about what’s happening. The next morning, they may not even remember what happened. If someone woke you during a sleep terror, you would have no idea why you felt so scared.

What to do about it: While common in young children, sleep terrors are not harmful, and they’re often scarier for parents than for the kids themselves, who don’t even remember their nighttime horrors the next day.

Parents should not try to wake the child up during a sleep terror, but should instead calmly monitor their safety during the event and act normally during the day. If the sleep terror tends to happen at the same time of the night, you can gently wake up your child half an hour before the usual terror time, which might prevent the sleep terror from happening.

5. Sleep paralysis and hypnogogic/hypnopompic hallucinations

If you’ve ever woken up completely unable to move, and perhaps felt a heaviness on your chest and a sense of fear or doom, you have experienced a sleep paralysis episode.

Along with the paralysis, people sometimes also see, hear, or feel things that aren’t there. These are called "hypnogogic" or "hypnopompic hallucinations." Usually, people describe seeing shadowy figures in the room or standing over their bed, or spiders crawling on their walls or in their bed. Sleep paralysis and related hallucinations have even spawned alien abduction theories.

What to do about it: Just like for most other parasomnias, consistently getting enough sleep, keeping a steady sleep schedule, and avoiding substances could help.

6. Exploding head syndrome

Now for the truly bizarre. Exploding head syndrome is when a person hears or feels a very loud noise in their head, usually during that blurry period just before falling asleep or just upon waking. The loud noises can feel like an explosion inside their head, though there’s usually no pain involved. Or they can also sound like loud banging or crashing, clashing pots, thunder, or electric crackles.

What to do about it: Sleep scientists don’t yet know exactly why this rare syndrome happens, but it seems that stress and emotional tension might make it more likely to occur. Usually, just putting a name to it and learning that it doesn’t indicate some serious medical issue is enough to help.

Parasomnia tips roundup

  • Ensure safety. Lock doors and put away car keys, keep sharp objects out of reach, and if necessary, sleep in a separate room from your partner.
  • Stabilize your sleep schedule. By keeping a steady biological clock, you can help your brain to transition between sleep and wake normally.
  • Get enough sleep. Sleep deprivation is a common trigger for parasomnias like sleep paralysis.
  • Minimize alcohol and drugs. Substances that affect your brain function can affect your sleep and dreaming, too.
  • Ask your doctor about your medications. Sometimes, medications prescribed for insomnia, depression, or other psychological disorders might induce parasomnias as a side effect.
  • Ask your doctor about getting a sleep study. Sometimes, symptoms like sleep-related hallucinations and sleep paralysis might indicate narcolepsy. Acting out dreams and having frequent nightmares might indicate a neurological or psychiatric condition, which also requires specialized care. Getting a full work-up with a sleep specialist can help to either reassure you or point you toward the right treatment.

Medical Disclaimer: All content here is for informational purposes only. This content does not replace the professional judgment of your own mental health provider. Please consult a licensed mental health professional for all individual questions and issues.

A version of this post also appears on Quick and Dirty Tips.

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