Why can't you sleep? Research suggests it is not just the stress of the teacher's job but their inability to unwind that may be the root of the problem.
And the answer may lie, not in vegging out in front of the television, but in finding an absorbing hobby or energetic sport that will distract you from your worries - although the hurly-burly of your family life may be equally effective.
Dr Mark Cropley, who is a health psychologist at the University of Surrey, has been looking closely at the relationship between teachers, work and sleep for more than 10 years. It is not, he says, a straightforward case of overwork leading to insomnia.
He says: "Teachers tend to work in the evening, but that's not necessarily the reason why they can't get to sleep. The problem for some is their inability to unwind or disengage from work.
"Teachers suffering from high stress carry on thinking about work even when they are watching television or talking to their friends."
In a study* published this year, Dr Cropley looked at the relationship between job strain, work rumination, and sleep patterns among 143 primary and secondary school teachers.
About equal numbers reported high job strain and low job strain; both groups showed a degree of unwinding and disengagement from work issues during the evening; but those reporting high job strain took longer to unwind and thought more about work all evening, right up to bedtime, than the other people studied.
Similarly with sleep, those under high job strain reported poorer sleep quality, leaving them less refreshed, than those under low job strain.
But both stressed and unstressed averaged only about six and a half hours'
Teachers are better able to unwind, suggests Dr Cropley, if they pursue a leisure interest that distracts them and gives them a sense of personal control. It might be dancing, making model airplanes, gardening, pub quizzes, climbing the wall in the local leisure centre. There is also something to be said for the distractions of family life.
A study** published in 2000 of family structure and blood pressure among teachers found the fall in blood pressure between work and home was greatest among parents and smallest among single people.
Dr Cropley and Derk-Jan Dijk, professor of sleep and physiology at the University of Surrey, offer teachers a number of practical tips for helping them fall asleep and stay asleep:
* Make a "to do" list before bed.
* Don't drink too much alcohol during the evening - "the older you get, the more alcohol disrupts sleep".
* Cut down on coffee consumption, in the evening and during the day as well.
* Keep your bedroom for sleeping in; don't use it as an office or for watching television. If you can't get to sleep or wake up in the middle of the night, don't lie there fretting. Instead get up and do something that is not work
* European Journal of Work and Organizational Psychology, June 2006, 181-196.
** Social Science and Medicine 50 (2000), 531-539.