Here's what you need to know about mumbling in your sleep. 

By Meghan Overdeep
July 17, 2019
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Whether it's complete nonsense or well-formed sentences, nearly 66% of the population has talked in their sleep in some form.

But as Rafael Pelayo, a sleep specialist with the Sleep Medicine Center at Stanford Health, recently explained to HuffPost, because sleep talking—or somniloquy—isn't a true disorder, there's really no demand for research on it. So, despite its prevalence, little is known about this common behavior.

Despite what you might have heard, there's no real meaning behind the words you say while you're asleep. According to the International Classification of Sleep Disorders, sleep talking does not reflect prior waking behaviors or memories, which means you're unlikely to jabber on about your day after you doze off—no matter how bad it was.

Talking in your sleep is usually harmless (and often hilarious), but there are some cases where it can be cause for concern.

It turns out that timing is everything with sleep talking. Pelayo told HuffPost that if you're over the age of 50 and suddenly begin talking in your sleep a lot, it could be sign that something's going wrong with your brain, or a symptom of an oncoming illness like Parkinson's disease or dementia. If you've been talking in your sleep your whole life, however, there's likely nothing to worry about. Sleep talking is very common in children and adolescents.

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As James Rowley, chief of the division of pulmonary, critical care and sleep medicine with the Detroit Medical Center Sleep, explained to HuffPost, sleep talking can also be brought on by stress, anxiety and depression. People with post-traumatic stress disorder are also known to talk or shout during their dreams.

"If sleep talking is associated with bad dreams, recurrent nightmares, snoring/witnessed apneas, there may be reason to discuss the recurrence with your physician," Rowley said. But odds are, you're fine.

"What needs to be stressed is that for the vast majority of people, sleep talking is harmless," Rowley concluded.

Unless of course, you're the exhausted person sharing a bed with said sleep talker!