Sleep talking, or somniloquy, is a form of parasomnia or abnormal sleep behavior. Other conditions classified as parasomnias include sleepwalking, night terrors and REM sleep behavior disorder (RBD).

Talking—or mumbling—in your sleep is not unusual or dangerous. It can occur in both REM and non-REM sleep. While there is very little in the way of clinical research on sleep talking, it remains a source of intrigue for many. Do we reveal our darkest secrets in our sleep? Do dreams impact what we say? Is sleep talking a sign of stress? Can it be cured? Here, we answer the most frequently asked questions about sleep talking.

1. Why do people talk in their sleep?

Sorry folks, but there’s really no good answer as to why we talk in our sleep. We know that sleep talking is prevalent and has been documented for a long time throughout history (there are papers from as early as 1892 on the subject.) However, it’s not so easy to study because its occurrence is random. 

However, some research points out that genetics may contribute to sleep talking. Similarly, people who sleepwalk, experience night terrors or have REM sleep behavior disorder are more likely to be sleep talkers. Some of these parasomnias may have a common cause, even if we don’t know yet what exactly the cause is. The likelihood of experiencing sleep talking is also higher if we also tend to experience nightmares, or suffer from sleep deprivation, sleep apnea or sleepwalking. 

Moreover, sleep talking can be triggered and can increase at certain times by:

  • Medication
  • Fever
  • Alcohol
  • Mental health conditions, such as depression or stress

2. How prevalent is sleep talking?

According to this study from Norway, there is a 66% chance that you will experience sleep talking at some point in your life. Since we generally aren’t aware of when we do it (and usually don’t remember it), it’s probably widely underreported. According to the American Academy of Sleep Medicine, the ongoing prevalence of sleep talking in adults is only around 5%

Sleep talking is also twice as common among people with post-traumatic stress disorder or psychiatric disorders and can be frequent in certain types of dementia or in people that experience seizures during sleep. 

3. Who talks in their sleep?

Anyone can experience sleep talking, and it happens in all sleep states and stages of the sleep cycle:

  • Stages 1 and 2: the speech of a sleep talker in the early stages of sleep might be easy to understand and make sense.
  • Stages 3 and 4: the sleep talker here is in a deeper sleep, and the speech might sound like moaning and, consequently, be harder to understand. In these stages, sleep talking can be confused with catathrenia – a separate condition in which people groan in their sleep. Unlike sleep talking, catathrenia harms sleep quality and can cause fatigue.  

However, children are more likely to talk in their sleep than adults, and there’s some indication that men may sleep talk more than women. 

4. Do dreams have anything to do with sleep talking?

While it’s easy to believe that what we say in our sleep has something to do with our dreams, we simply don’t know much about the relationship between dreams and parasomnias. The science can’t confirm or exclude the possibility that sleep talking is to some extent based on dreams.

The paper, “Sleep talking: A viable access to mental processes during sleep,” published in Sleep Medicine Reviews in 2019, allows that there may be an overlap of sleep talk and dream content. However, it’s still speculative. Just as it’s hard to study sleep talking, it’s not easy to get reliable measures of dream content.

An interesting citation from the paper illustrates the difficulties in establishing if sleep talk is related to dreams. “A large number of sleep speeches merely consist of short expressions of assent or negation (e.g., ‘OK’, ‘no,’ ‘good,’ ‘mm-hm,’ ‘uh-huh,’ ‘no!’ ‘stop!’ ‘don’t!’, etc.) and sound like half a conversation or an attempt to contact another person, often with pauses during which the ‘other’ replies.”

5. Do the words we speak in our sleep mean something?

Sleep talking episodes tend to be short and rarely involve long conversations. In fact, an episode may just involve a bunch of words and unmeaningful sentences. A study from 2017 looked at people with REM sleep behavior disorder, sleep talking, sleepwalking or sleep terrors. From the speech episodes recorded, they found that:

  • 59% contained non-verbal addresses—mumbles, shouting, whispers
  • “No” was the most frequent word
  • Verbal abuse lasts longer in REM sleep and was mostly directed towards insulting or condemning someone
  • Swearing was more prevalent in non-REM sleep
  • Men sleep talk more than women during a night and use a higher proportion of swearing
  • 15.5% of words belong to a foreign language!

What does it all mean? That is still much of a mystery. If anything, the study highlights the difficulty in discerning meaning from the content of what is said during a sleep talking episode.

6. Should you seek treatment for sleep talking?

Sleep talking, in itself, is typically not a cause for concern. In most situations, treatment is not necessary because of its random occurrence and minimal negative consequences. But if you suddenly start sleep talking as an adult, and especially if it leaves you feeling tired during the day or if you experience sleep or mental health problems, then it’s a good idea to seek professional help. As said, people with PTSD or mental health issues might be more prone to become sleep talkers.

7. How can you stop talking in your sleep?

Since we don’t know why we do it, we don’t really have good information on how to stop sleep talking episodes, and there is no such thing as a “cure”. If you are a sleep talker, and awakening that part of the brain which produces speech, then some good advice is to think about your sleep routines and regularity for better sleep hygiene. Research points out that most parasomnias may be triggered when sleep patterns are disturbed. Therefore, improving your sleep environment and sleep habits are key to preventing future episodes. Some tips to improve your sleep hygiene are: 

  • Avoid caffeine or other stimulants in the evening.
  • Keep a consistent sleep schedule, especially during the weekends. Avoid naps late in the day
  • Make sure that your bedroom is a sleep space free of bright lights or sounds, and with an adequate temperature (21-23 °C or 67-70 °F).
  • Limit the use of electronic devices before bedtime, giving yourself time to relax and meditate
  • Exercise during the day, or go for a walk to get some daylight. 

8. When can sleep talking become problematic?

Even though sleep talking is generally not problematic, if talking in your sleep disturbs a roommate or a bed partner, it can be a problem. You could also feel stressed about cursing or saying something embarrassing in your sleep, which could make you feel more stressed about going to sleep. This in turn could increase the risk of sleep problems.

Are you worried about revealing deep, dark secrets that your partner will hear? Worry not. While it’s a great plot device for a TV drama, revealing secrets while sleep talking is probably unlikely to occur. According to a study, it’s not the best method to get someone to reveal their secrets!

9. Are other parasomnias like night terrors dangerous?

Night terrors (also known as sleep terrors) are different from sleep talking and nightmares. With a night terror, the person might sit up in bed, utter screams, or appear genuinely terrified of something. Night terrors usually happen when arousing from deep sleep, mainly at the beginning of the night. They can increase with fever and too little sleep the previous night(s). 

Night terrors are quite common in children. Approximately, 40% of children under age 5 experience night terrors. While it can be traumatic for parents to see their children experience a night terror, kids tend to grow out of it. Children commonly don’t remember anything from the episode. In this sense, night terrors are also different from nightmares. In contrast to night terrors, it is common that we wake up and remember the nightmare that terrified us, and nightmares typically happen during REM sleep while night terrors are mainly related to deep sleep.

10. What can I do if my child has night terrors?

Making sure your child isn’t sleep-deprived is important. One of the reasons it’s believed to affect children is that in childhood we have a lot of deep sleep, and sleep and the brain are still maturing. With age, we get less deep sleep. Reducing stress, having a regular sleep schedule, and having good sleep habits, in general, are key factors. If your child often experiences night terrors, you can try to gently wake the child during a short moment before the time when the night terror typically occurs.

11. What causes sleepwalking?

Sleepwalking and night terrors seem to share similar causes in terms of deep sleep and improper arousal—when you’re somewhere in between awake and asleep. Like night terrors, sleepwalking is more common in kids than adults. Studies have shown that sleepwalking is linked to sleep deprivation and other insomnia symptoms. However, it’s generally advised that if there’s an underlying reason for sleepwalking, such as Obstructive Sleep Apnea (OSA), Restless Leg Syndrome (RLS) and so on, you should treat it to effectively diminish the episodes.

12. What is REM Sleep Behavior Disorder (RBD)?

REM Sleep Behavior Disorder is another type of parasomnia. It involves rapid movements and vocalizations associated with vivid dreams during the REM sleep phase (when the body should experience temporary muscle paralysis). It’s believed that less than 1% of people suffer from this condition, and it usually requires treatment due to the risk of injuries to oneself and the bed partner from acting dreams out. Like sleep talking, science hasn’t been able yet to find the cause of RBD, even though some studies suggest that it is related to a disruption in the neural pathways that inhibit muscle activity during the REM phase.