Shift Work Sleep Disorder: a Circadian Rhythm disorder resulting from a work schedule that takes place during the normal sleep time. It affects people who work at least some part of the night or who frequently rotate shifts. Their bodies never really adjust to displacing sleep to another part of the day.
A shift worker is anyone who follows a work schedule that falls outside of the traditional nine to five daytime schedule. Many fields commonly involve shift work, including:
> medicine (doctors, nurses, technicians)
> law enforcement or security
> travel (pilots, air traffic controllers, taxicab drivers, engineers)
> Industry (commercial truck drivers)
It is easy to understand why shift work has become popular. A 24 hour work force increases production. However, the benefits of perpetual productivity carry with it inherent risks. Compared to traditional workers, shift workers experience more sleep disturbance, resulting in less sleep over time. Frequent sleep disturbance leads to daytime sleepiness. Sleepiness in the work place leads to poor job performance, errors, accidents, and injuries.
Shift Work Sleep Disorder develops when a person fails to adapt to shift work, even after a period of adjustment. The problem is that the shift work schedule demands wakefulness when the body wants to sleep. The only time remaining for sleep is when the body expects to be awake. People who work overnight or early morning shifts often report the most problems. They sleep up to four hours less than average.
Some people adapt to shift work without much problem. A sleep specialist can be of help when efforts to simply sleep at an alternate time fail. A two week record of your sleep patterns using a sleep diary is often enough to diagnose this condition. The log should reflect: bedtime, the time it takes to fall asleep, the number and duration of awakenings during the night, and the time you arise from sleep. Testing in a sleep laboratory may be necessary if another sleep disorder is suspected.
Treating Shift Work Sleep Disorder involves resetting your internal clock to accomodate work during the night and sleep during the day. Some employers offer techniques to help employees adapt to shift work, which should include:
> limited use of rotating shifts
> shifting forward in a rotating shift
> the use of bright lights in the work place
> exercise breaks
> regular rest breaks
Otherwise, treatment is twofold:
Good Sleep Hygiene: habits that are conducive to good sleep. Getting all of your sleep at once, at the same time each day is an example of good hygiene for shift work. Also, avoiding caffeine after noon and alcohol within four hours of bedtime will help.
Bright Light Therapy: resets the internal clock by using a full spectrum lamp or portable visor set to 10000 lux for 30 to 90 minutes immediately upon awakening, or just before getting up. Exposure to sunlight at this time may also help. Bright light should be avoided within a few hours of your designated sleep time, so your body can prepare for sleep.
Shift Work Sleep Disorder Mechanics
Shift Work Sleep Disorder is a circadian rhythm disorder or one that affects the natural timing of sleep and wakefulness. Circadian rhythms involve an internal clock, which correlates to the 24 hour cycles of night and day on earth. This clock drives us to sleep at night, for about eight hours. It also drives us to feel awake during daylight hours, when sunlight is present. Sunlight keeps us awake, and darkness makes us tired. Exactly how shift work affects the sleep cycle depends on the hours we work:
Night (Graveyard) Shifts: Working an overnight shift, usually from 11:00 p.m. to 7:00 a.m. displaces the entire sleep time. People working this shift tend to feel extremely tired on the job and are more likely to make mistakes.
Early Morning Shifts: A work cycle that begins between 4:00 a.m. and 7:00 a.m. displaces the latter half of the sleep time. People working this shift tend to have trouble falling asleep earlier, as well as waking up earlier.
Late Night Shifts: Working a shift that ends between 11:00 p.m. and 3:00 a.m. displaces the first half of the sleep time. People working this shift sometimes wake up before they have compensated for time lost earlier in the night.
Rotating Shifts: Shifts that alternate displace varying parts of the sleep time. People working this shift tend to feel very tired most of the time because there is no reliable time for sleep or wakefulness.