The stress of daily life has sparked¹ a new phenomenon - sleep texting.

日常生活的压力引发了一种新现象——发“睡眠短信”。

People with the rare condition send incoherent（语无伦次的） text messages while asleep to their friends and family - completely unaware² that they are doing it.

Sleep specialist Dr David Cunnington, of Melbourne Sleep Disorder³ Centre in Australia, said patients had reported incidents of sleep texting - and he has advised people to leave their mobile⁴ phones outside the bedroom.

He said: 'We have had patients who have reported sending text messages to their friends and family while asleep.

'It is one of those things that happens, but it is very rare, and certainly not a common trend.'

Unsurprisingly, there are no studies into sleep texting - but a similar phenomenon, sleep emailing, was studied in 2008.

Researchers at the University of Toledo reported the case of a woman, 44, who would compose emails while sound asleep（睡熟） . She had no recollection of sending the emails when awake.

Dr Cunnington said cases of sleep emailing were more common, and were likely to have a more detrimental⁵（不利的） effect on the lives of sufferers.

He said: 'Emails can be sent to work colleagues and have much more serious consequences, whereas⁶ text messages are more likely to be accidentally⁷ sent to a friend or family member, so people aren't as likely to complain of a problem.'

Dr Cunnington described sleep texting as the result of people having too much to do during waking life.

He explained: 'People are doing so much during a normal day that it can mean that they feel like they're "on call" even at night.

'Because it's so easy to receive emails constantly, and get notifications from smartphones, it becomes more difficult for us to separate our waking and sleeping lives.'

Dr Cunnington said people struggling to get a quality night's sleep should keep their phones out of the bedroom.

'The key point is that people need to respect their sleep, and make an effort to switch off at night.'