What Is Shift Work

Try to find a definition of shift work and you will come up with six different answers from every seven people you ask, because just about every employer, whether government department or private company, structures its shift pattern differently. For our purpose though, we will simply define shift work as working outside of the normal working day – which used to be 9 a.m. to 5 p.m. and is increasingly becoming more like 7 a.m. to 6 p.m.

Outside of these hours shift work can involve working in the evenings, through the middle of the night or in the early hours of the morning. It can also encompass working overtime or working extended days.

Shift work can also follow a regular or "permanent" pattern, working the same shift day after day, or a "rotating" pattern, for example, moving from working in the evening to working through the night and back again, or moving from working a normal day to working in the evening and back again. The combinations are almost endless.

Night watchmen, coming on at 7 p.m. every day and working through to 7 a.m. and restaurant waiters, starting at 5 p.m. each day and finishing at 1 a.m. might be examples of individuals working a permanent shift pattern. Police officers, on the other hand, will often work a rotating shift pattern, perhaps working through the night from 6 p.m. to 6 a.m. for a week, then having a couple of days off before starting a week of day shifts from 6 a.m. to 6 p.m.

The variety of shift patterns, both in terms of the hours worked and whether or not these hours are fixed or rotate, means that a wide variety of different sleep problems arise out of shift work. As we progress though, I’ll try to steer a middle course and look at these problems in general terms for the sake of simplicity.

Before moving on however let's just take a slightly more detailed look at the broad categories of shift work.>>>