Has someone ever told you that you talk in your sleep? It's more common than you might think. Research suggests around 50% of children aged between 3-10 years talk in their sleep. Around 5% of adults also talk in their sleep.

Talking in your sleep – called somniloquy – isn't harmful to your health. It's a parasomnia – a kind of abnormal sleep behaviour. Some people will hold whole conversations – they will even ask and answer questions – whereas others might utter steams of incoherent words or babble.

Usually, sleep talking occurs during REM sleep, when a person is dreaming. It might be accompanied by sleepwalking or other movement during sleep. You don't have to wake a sleep-talker up – as they progress to the next stage of sleep they should stop talking.

The content and coherency of sleep talking varies per person. Some people mumble to themselves, while others might shout and yell, or carry on conversations with you or with some imaginary person. Some people can get quite graphic and vulgar, which can cause problems if young children can hear the sleep talking.

If you share a room with a sleep-talker and their sleep talking keeps you up at night, you may need to look into a cure for insomnia.

Sleep talking is more common in children, and they usually grow out of it by their teenage years. Some people continue sleep talking into adulthood, and some research suggests sleep talking might even run in families.

If your partner tells you that you're a sleep talker, there's probably not much you can do about it. The best idea is to see a doctor to figure out if you have any related sleep issues, and maybe buy your long-suffering roommate some earplugs!

For more information about insomnia and sleeping problems you can visit the Sleep and Insomnia Guide