Why Do Some People Talk In Their Sleep?

But why does it happen? And is it dangerous? Most importantly, can a jealous lover use it to extract information about your past relationships and how you truly feel about them now, like in that one movie you saw?

Well, truth is, we’re not exactly sure about a lot of it.

What causes sleep talking?

In most cases, there’s no precise cause of sleep talking. It’s just one of those weird things that the body does sometimes, like hiccupping or pee shivers.

If you’ve been told you’re a chatty snoozer, though, don’t worry – you’re not alone. In fact, you’re in the majority: studies suggest that as many as two out of three people sleep talk at some point in their lives. 

That statistic is even higher for kids, with half of young children exhibiting the behavior at some point. That’s a simple result of their age: their brains are less mature, and so less able to switch between wakefulness and sleep quite as smoothly as an adult’s; they also need more sleep, and less interrupted sleep, than an adult – meaning there’s simply more chance for the parasomnia to manifest.

“Babies, toddlers, and young children have a higher proportion of REM sleep to non-REM sleep,” explained June Seliber-Klein, a sleep medicine specialist and chief medical officer at Ognomy Inc – and sleep talking, like other parasomnias, “is a normal feature of REM sleep at times,” she told sleep.com in 2023.

Even in adults, it’s still about one in twenty of us who occasionally natter away in our sleep – not common, but hardly super-rare either. And while there are a few things that make it more likely – mental health difficulties such as anxiety, depression, or post-traumatic stress disorder (PTSD), for example – the biggest factor seems to be simple genetics. It seems to run in families and often turns up alongside other parasomnias like teeth-grinding, nightmares, or sleepwalking. 

There are some environmental factors that can increase the likelihood of sleep-talking. Many come down to being stressed out: when your brain is overloaded with work, study, money, social obligations, and everything else that comes with modern life, it can sometimes struggle to switch between sleep and wakefulness. That, in turn, leads to parasomnias – “you’re asleep, but part of your brain hasn’t quite transitioned to sleep mode,” Milena Pavlova, a neurologist at Mass General Brigham and medical director of the Clinical Sleep Laboratory at Brigham and Women’s Faulkner Hospital, explained last year. “So, you keep doing things in your sleep that normally happen during wakefulness.”

Alternatively, sleep-talking might simply be a symptom of being unwell – or a side effect of treatment. It often happens in people running a high fever, for example, or under the influence of drugs or alcohol. And we don’t only mean illicit drugs, either: certain medications, including some antidepressants, asthma meds, or sleep aids like Ambien, have also been linked to talking in your sleep.

Is it dangerous?

Sleep talking is usually not dangerous. Annoying for roommates and partners, sure, but not dangerous.

“In the majority of cases, sleep talking is harmless,” confirms the Sleep Foundation. “It doesn’t usually have a major effect on the person’s sleep, and it normally doesn’t occur frequently enough to cause any serious problems.”

That said, there are a few cases where it might be a symptom of something more dangerous. It can be associated with sleep apnea, for example – aka the “your body randomly forgets that it needs to breathe” disorder. If whatever is behind it also causes sleepwalking, meanwhile, you might end up wandering into trouble while you snooze.

Sleep talking may also be a sign of sleep disorders like night terrors or RBD – an initialism which stands for REM behavior disorder, which in turn stands for rapid eye movement behavior disorder. If that’s the case, though, you’d probably notice: “RBD can start with benign talking but transition into shouting and gradually turn into violent actions,” Pavlova explained. 

“[Sufferers] might try kicking or punching air,” she added. “Some may fall right out of bed.”

What to do about sleep talking

Given it’s pretty normal and not dangerous, there’s not much you need to do about sleep talking – which is lucky, really, since there’s also not a whole lot you can do about it. 

“Because the cause of sleep talking is not fully understood, there is limited knowledge about proven methods to stop sleep talking,” admits the Sleep Foundation. However, it advises, “for people who want to try to limit or eliminate sleep talking episodes, focusing on sleep hygiene may be a helpful starting point.”

That means getting to bed on time, every day; it means avoiding caffeine in the afternoon and evening, and staying away from screens and blue light. It means living healthy, getting exercise, and, you know, all that other boring stuff. “We want our bodies to feel as ready as possible to go to sleep,” advised Pavlova. “Disruptors do the opposite.”

If you’re doing all that and still feeling rough in the morning, though, it may be a good idea to talk to a doctor. 

“If your sleep talking occurs suddenly as an adult, or if it involves intense fear, screaming or violent actions, you should consider seeing a sleep specialist,” said Michelle Drerup, a behavioral sleep medicine specialist at the Cleveland Clinic, in 2024. “Your doctor may order a sleep study to rule out contributing sleep disorders, like sleep apnea or periodic limb movement disorder.”

Which only leaves one question…

Can somebody find out my deepest, darkest secrets from sleep talking?

Ah, yes – the classic movie trope: a spy or traitor infiltrates their enemy, only to be found out when they fall asleep and start reciting their plans. Or the opposite: a stoic love interest confesses their feelings only when asked in their sleep. It’s certainly a good plot device – but is it accurate?

Well, don’t fret: you’re probably not going to spill your guts while you snooze. In fact, you’re not all that likely to make any sense at all – in a 2017 study of more than 200 people and almost 900 sleep-talking episodes, researchers found that almost two-thirds of the utterances made weren’t even words. Most of what was intelligible was either the word “no” or various questions, and a lot of them were swears. 

We’re not all that sure what people are talking about when they’re sleep-talking – sometimes it seems dream-related, sometimes not – but the fact that a lot of it seems to be negative or rude, and that it involves things like proper grammar and pauses for replies, hints that it might sometimes just be people acting out arguments in their sleep. It’s difficult to know for sure, though, since people who sleep-talk don’t generally remember it, and anyone forced to listen to their one-sided conversations likely won’t be able to glean enough sense to understand it entirely.

One thing we can be sure of, though, is that it’s not a handy hack to uncovering your sleep-partner’s deepest secrets.

“If you’re looking for an elixir of truth, sleep talking isn’t it,” Pavlova confirmed. “That’s a myth that’s persisted for decades.”