Why the Night Shift Makes You Sleepy
Why do night shifts wreak havoc on sleep? "The circadian rhythm is so [ingrained] in each one of us that what we're doing is going against the body's natural desire to be asleep at nighttime and to be awake during the daytime," says Fleming. "Some people have ways of coping that are better than others, but for the most part, it's very difficult to feel your optimal self when you work the night shift."
Rotating shifts are even harder on the body, Fleming adds. "The body likes to operate on a routine schedule. The body likes to know what to expect in terms of production of certain hormones," he says. "When you expose yourself to sunlight at some times during the week, but not others -- when you're sleeping at nighttime some nights and then during daytime at others -- the body has difficulty knowing what to anticipate and when to produce those transmitters and neurochemicals for sleep and digestion and proper functioning of the human body."
Regular, restful sleep is crucial for the body's repair, Fleming says. "The body's ability to recover and recuperate from the damage done during the daytime on a cellular level is affected by the night shift --because that's the purpose of sleep. If our sleep schedule is erratic or irregular, that synchrony of repair that's supposed to happen at nighttime doesn't get played out the way it's supposed to."
Treating Shift Work Sleep Disorder
Despite the prevalence of irregular work hours in our 'round-the-clock, technological society, sleep experts told WebMD that people usually don't show up at sleep labs with complaints about topsy-turvy schedules. "Most patients feel that there's nothing they can do about it," Fleming says. "It's not a very common source of referrals to a sleep center, even though it should be."
The hallmarks of shift work sleep disorder are excessive sleepiness during night work and insomnia when a worker tries to sleep during the daytime. Workers with significant symptoms -- including headaches, lack of energy and trouble concentrating -- should talk to their doctors.