Circadian rhythm disorders occur when the body’s natural sleep-wake cycle is disrupted and the individual is not able to sleep at the appropriate time. Two commmon conditions are going to sleep much later (delayed) or much earlier (advanced) than ancitipated, but the single most common ways in which these problems arise is when a person chooses or is required to work on an unusual schedule (shift work) or travels so much they must adopt another schedule (jet lag)

Night shift work is very common in the United States and many other countries. This schedule means that sleep must occur during the day or afternoon.  And, given all of one's other personal and social obligations and responsibilities, you can imagine how difficult it would be to gain a full period of restful slumber. 

Many people who work night shifts or who travel a lot resort to sleeping pills.  Others find they just sleep less hours and then use more caffeine or stimulants during their night shift.  Then, one of course the big issue is what do you do on the nights you're not working?  Do you go to sleep as if you didn't work nights?  Or, do you stay up and go to sleep according to the system you have in place for your night shift schedule?

These are not simple problems that have simple solutions.  In fact, shift work or jet lag problems are notoriously underappreciated, underresearched and undertreated.  Worse, there are no truly definitive treatments for either of these problems.  There are all sorts of behavioral steps you can try, medications to consider, and even attempt to influence your schedule with bright light therapy, melatonin, or chronotherapy (altering bedtimes intentionally to speed up adjustments).  And, for those with serious sleep problems arising out of shift work, it certainly can prove worth your time and effort to meet with a sleep medicine specialist to develop a detailed treatment program to improve your situation, because the techniques described above may produce very real benefits.

Now, though, I want to leave you with one thought, because it is the most important insight that I have ever noticed about this problem.  It's really 2 points in one.  First, in 20 years of conducting sleep medical research, I have always been impressed by the number and types of people who report either that shift work or jet lag is absolutely no problem with respect to sleep or that either of these conditions or both cause major problems.  In my own clinical practice of emergency medicine some years ago, this dichotomy was quite apparent.  Some doctors hated shift work and working nights in particular and some never saw it as a big deal.

Now, the part that remains most interesting to me as a researcher and a clinician is that the people who hated shift work or busy travel schedules almost always had another sleep disorder that they did not recognize.  The most common conditions were either sleep breathing disorders or sleep movement disorders.  

Through the years, I've noticed the same phenomenon in vast array of shift workers and those who travel regularly.  Those who suffered the most from working nights, shifting schedules, or traveling a lot almost always suffered from an undiagnosed breathing or movement disorder.  Those who didn't mind shift work or never suffered jet lag, almost always appeared to be relatively normal sleepers.

Therefore, in my clinical judgment, when individuals report major complaints with shift work or excess travel, one of the first things I want to test is their actual sleep quality in the sleep lab.  Many of these sleep patients are surprised that I so strongly make this recommendation, and surprise grows even larger when we detect a physical sleep problem in the equation.  And, the most exciting finding here is that many of these patients do report an easier time managing their shift work or travel schedules once these underlying sleep disorders are addressed.