When you think about it, sleep is a kind of wild phenomenon. Ideally, you get seven to nine hours every single night to become even better friends with your bed, have a completely legitimate reason not to answer emails, and, you know, do things like consolidate memories and rebuild muscle. But sometimes people experience truly wild nocturnal events called parasomnias, which is the umbrella term for sleep disorders that happen while you’re falling asleep, sleeping, or waking up.
Parasomnias can include everything from having more terrifying than usual nightmares to driving in your sleep (yes, really). In general, these sleep disorders are more common in kids because their brains are still developing, according to the American Academy of Sleep Medicine (AASM), but adults certainly aren’t immune.
“There’s a normal process for transitioning between [being] awake and asleep and asleep and awake,” Jesse Mindel, M.D., a sleep medicine specialist with The Ohio State University Wexner Medical Center, tells SELF. “Parasomnias happen when that transitional phase doesn’t [occur] properly.”
So, about those sleep transitions. When you’re sleeping, you cycle through several stages of rest. You spend about 75 percent of your non-waking time in the first four stages of sleep, which are categorized as non-rapid eye movement (NREM), according to the National Sleep Foundation. Many parasomnias that happen in NREM sleep are considered arousal disorders because parts of the brain “wake up” while others remain dead to the world. Also known as partial arousal, this can happen due to issues like loud noises and breathing problems that interrupt your rest, Lawrence Epstein, M.D., assistant medical director in the division of sleep and circadian disorders at Brigham and Women’s Hospital in Boston and an instructor at Harvard Medical School, tells SELF.
Then there’s rapid eye movement (REM) sleep, which is considered the “dreaming state” of rest. It happens about every 90 minutes and gets longer as you continue to sleep, the National Sleep Foundation says. While people with NREM parasomnias are considered partially awake, people who experience REM parasomnias are fully asleep and dreaming. Instead, the brain processes that keep people with REM parasomnias from moving around while they rest aren’t as active as they should be.
In general, having the occasional parasomnia is typically harmless, according to the AASM, but a few—namely some REM parasomnias—can be more concerning for various reasons.
So, how do you know if what you might think of as a quirky sleep habit is actually a parasomnia? Here’s a look at nine parasomnias—and what to do if you experience them.
1. Confusional arousals
If you wake up feeling disoriented or acting strangely (read: you’re speaking slowly or are answering questions weirdly), you could be experiencing a confusional arousal. This is sometimes called sleep drunkenness, but it’s less fun than it sounds.
Confusional arousals usually happen when something wakes you up during the first third of the night, when you’re engaging in NREM stages of rest that are sometimes called slow-wave sleep, according to the AASM. While experts don’t know for sure what happens in the brain during slow-wave sleep, it’s thought to help the brain recover from the day. So, when you wake up during slow-wave sleep, your mental capabilities are pretty significantly decreased, and it can take up to 30 minutes for full cognitive functioning to return, according to the American Sleep Association (ASA). Hence symptoms like being confused and talking about things that make absolutely zero sense.
Since confusional arousals tend to happen when something wakes you up, risk factors include things like dealing with a lot of loud noises when you sleep, along with disorders like sleep apnea, which can cause you to wake up because you stop breathing while asleep. Lifestyle factors that may interrupt your sleep, like alcohol use, can also contribute. And rebounding from sleep deprivation can trigger these episodes since, after a lack of sleep, you spend more time in the restorative NREM slow-wave sleep stages linked with these parasomnias, Vsevolod Y Polotsky, M.D., Ph.D., a professor of medicine at the Johns Hopkins University School of Medicine, tells SELF.
Confusional arousals usually aren’t harmful. You probably won’t even remember them and may only know about them because a partner clues you into their occurrence. But if they are recurring and bothering you, lifestyle changes like cutting back on alcohol, treating any other underlying sleep disorder, and trying to regularly get a full night’s rest may help you avoid future episodes. You can talk to your doctor for more guidance.
2. Sleep walking
This NREM parasomnia, also called somnambulism, typically involves getting up and stumbling around while you’re still asleep. Like confusional arousals, sleep walking happens during those partial arousals when some areas of your brain are awake while others are not.
When a person sleep walks, some parts of the brain that manage higher-level functions (à la memory or planning) like the cerebrum and cerebral cortex appear to remain “offline.” This means that the behavior sleep walkers exhibit tends to be pretty basic, as Dr. Mindel explains, like ambling through the house or rummaging through a closet. “Sleep walkers also tend to be suggestible,” Dr. Mindel says. That means that a simple, “Hey, why don’t you go back to bed?” with a very gentle nudge might do the trick.
It is unclear exactly why people sleep walk, but some researchers believe that it’s actually a form of disassociation where the sleep walker cycles between states of being asleep and awake very quickly.
Most sleep walking episodes are short and not a big deal. However, it’s worth noting that in rare cases, medications like sedative hypnotics that are regularly used to treat insomnia can cause longer, more sophisticated episodes of sleep walking that can even include activities like driving, says Dr. Mindel. These meds appear to bind to receptors in the brain that may allow someone to move around more than usual while staying asleep, he explains.
Occasional sleep walking doesn’t typically need to be treated, the Mayo Clinic says. But if your sleep walking unnerves you or is possibly putting you or others in danger, talk to your doctor. They can help you evaluate factors that might be contributing to your sleep walking by causing partial arousals. And to reduce frequent sleep walking, sometimes doctors prescribe medications such as benzodiazepines, which reduce the brain’s activity in a way that may prevent wandering around while you sleep.
3. Sleep talking
As the name suggests, sleep talking (or somniloquy) is a parasomnia that involves talking in your sleep—though this “talking” can range from moans and nonsensical words to monologues and conversations. It can happen during any stage of sleep, and the lighter the sleep stage, the more likely you are to make sense, according to the National Sleep Foundation.
Researchers aren’t exactly sure what causes someone to sleep talk, but they suspect that specific parts of the brain that keep us from chattering in our sleep might “wake up,” essentially, and allow us to talk. Episodes can be triggered by lifestyle factors like sleep deprivation, stress, alcohol use, and even fever, according to the AASM. But it is worth noting that sleep talking often occurs in conjunction with other sleep disorders such as nightmare disorder, confusional arousals, and sleep apnea, the National Sleep Foundation says.
Randomly talking in the middle of the night can be pretty jarring for anyone who overhears you, but sleep talking itself isn’t a major reason to worry. To minimize sleep talking episodes on your own, it might help to practice good sleep hygiene habits including sticking to a regular sleep schedule, getting a full night’s rest, and not drinking too much alcohol before bed. Since sleep talking can be connected with so many other conditions, if it persists you might want to talk to a medical professional to see what else could be going on.
4. Sleep-related eating disorder (SRED)
People with SRED partially wake up during NREM sleep and binge, often on combinations of high-calorie, high-carb, high-fat foods, according to the Mayo Clinic. Many people with SRED have an episode nearly every night, and they can happen more than once a night as well.
Risk factors include having an eating disorder such as bulimia or anorexia, a mental health condition such as anxiety or depression, and a history of sleep talking, according to the Mayo Clinic. But SRED can also cause an increased risk of issues like depression or disordered eating because of the shame or embarrassment, which could then cause you to undereat or over-exercise the next day.
SRED can be concerning. You could eat something toxic, burn yourself, or even cause a fire, the AASM explains. It’s best to see a sleep doctor if you notice symptoms like waking up to evidence that you’ve eaten in the night. Getting regular sleep and making sure the path from your bedroom to your kitchen is safe are common ways to manage SRED, and a doctor can counsel you on medication options like antidepressants.
Yes, if you have sexsomnia you can have sex, moan, thrust, masturbate, or engage in any other number of sexual activities in your sleep. This NREM parasomnia describes sexual behaviors that happen during sleep, according to the American Sleep Association. Researchers aren’t quite sure what causes it, though it does appear to be associated with confusional arousals. Many people who experience sexsomnia have also been diagnosed with other NREM sleep parasomnias.
As is true with many other parasomnias, one potential danger here is injury to yourself or someone else. There can be other consequences, too. If you’re having sex with a partner while partially asleep, consent is not possible. In some instances, sexsomnia has been discussed in sexual assault and rape cases.
Treatment for sexsomnia often involves improving your sleep hygiene, treating underlying sleep problems, taking sedating medications, and using specialized alarms that wake you up if you start moving too much, according to the International Society for Sexual Medicine.
6. Night terrors
One second, you’re lying in bed. The next, you’re shrieking, kicking, thrashing, or shouting things that other people can’t understand. Then, when you wake up, all you can remember is the horror. This is a typical night terror (or sleep terror) episode.
This NREM parasomnia occurs when a person is transitioning from the deepest stages of NREM sleep into REM sleep, the AASM explains. Unlike nightmares, which often have a narrative structure that you remember when you wake up, during night terrors most people report only remembering a feeling of all-consuming fear.
If you have night terrors frequently, you (or anyone you share a bed with) could be at an increased risk for injury, because you might try to escape your bed or even fight. You might also be totally exhausted the next day, which isn’t completely surprising when a sense of complete terror jolts you out of sleep.
Keeping a sleep diary and connecting with a sleep specialist could provide clues as to what could be contributing to your terrors, the AASM says. That may also help you address any underlying medical issues that could be contributing, like sleep apnea.
7. Nightmare disorder
Nightmare disorder is a REM parasomnia that occurs when you have regular nightmares that are so scary they wake you up. Pretty much everyone has nightmares, but they can become a disorder if they’re really distressing and impacting both your sleep and your day-to-day. “The episodes can become so terrifying that they make it hard for someone to be willing to go to sleep,” explains Dr. Epstein. This can become a vicious cycle, with sleep deprivation prompting you to have even more nightmares, according to the AASM.
As you’re probably aware, issues like stress and anxiety can predispose you to nightmares, as might sleep apnea and insomnia. Both trauma and resulting post-traumatic stress disorder (PTSD) can also increase your risk for nightmare disorder, says the AASM. Certain medications, like some antidepressants, may also have nightmares as a side effect.
If you’re worried about your nightmares, talk to your doctor or therapist. Counseling, stress management, and systematic desensitization—when you slowly start to expose yourself to the frightening contents of your dreams in an effort to change your reaction to them—are all treatment options, according to the AASM.
8. Sleep paralysis
Few things sound more terrifying than waking up, not being able to move, and being convinced a demon is sitting on your chest. Unfortunately, for people with sleep paralysis, this might be just another night. This REM parasomnia involves being unable to move your body for a few seconds or minutes when falling asleep or waking up, according to the National Sleep Foundation. People who have experienced it often talk about horrifying images and sensations, like being attacked by a supernatural force. But what’s actually going on?
During REM sleep, your brain relaxes your muscles to the point that you’re more or less rendered immobile. The process is called atonia, and it keeps you from acting out your dreams, explains Dr. Epstein.
“In most people, if you’re woken up from dream sleep, this sleep paralysis goes away right away. But for some people, that doesn’t happen and paralysis can linger into wakefulness,” he says.
Episodes of sleep paralysis do usually end on their own (or might stop if someone touches you or talks to you). And isolated incidents typically aren’t a major cause for concern. But recurring episodes are sometimes linked to narcolepsy, a sleep disorder that involves drowsiness and sudden sleep attacks.
Lack of sleep can additionally increase the risk of sleep paralysis. But sleep paralysis can also be triggered by stress or related to mental health conditions like bipolar disorder, according to the AASM.
If you’re experiencing persistent sleep paralysis or if the episodes are making you anxious, you should see a doctor. In addition to addressing lifestyle factors that may be contributing, antidepressants called selective serotonin reuptake inhibitors can suppress REM sleep, which might help alleviate symptoms, according to the Mayo Clinic.
9. REM sleep behavior disorder
This is the parasomnia doctors say they tend to worry about most. REM sleep behavior disorder can cause you to act out your dreams in a way that could be harmful, according to the AASM. You might kick to fend off an imaginary intruder or try to outrun a monster in your nightmare—basically do anything physical that might lead you to hurt yourself or your bed partner.
People with REM sleep behavior disorder lose the ability to remain immobile during REM sleep, explains Dr. Epstein. It appears as though for some people this phenomenon is linked to antidepressants, though experts aren’t sure how strong this connection may be and why it might exist. Narcolepsy is another risk factor. Oddly enough, in some people, REM sleep behavior disorder can be a predictor of neurodegenerative illnesses such as Parkinson’s disease, Dr. Epstein says. The link is a protein called alpha-synuclein, which can build up in the brain and kill brain cells in the area responsible for keeping that paralysis turned on, says Dr. Mindel. This build-up is known as a Lewy body, and it is often a hallmark of diseases like Lewy body dementia and Parkinson’s.
That doesn’t mean you definitely have a neurological condition if you’re dealing with REM sleep behavior disorder. But in any case, it makes sense to see a doctor or sleep medicine specialist if you think this is what you’re dealing with. According to the Mayo Clinic, the benzodiazepine clonazepam helps reduce the number of REM sleep behavior episodes some people experience. There’s also significant scientific interest surrounding whether melatonin supplements, a synthetic version of a human hormone that helps induce sleep, may help manage the disorder. But research hasn’t found enough evidence to show that melatonin can definitely help, and you should always talk to your doctor before adding any kind of supplement to your routine.