It doesn’t take much to throw your circadian rhythm (your body’s internal sleep clock) completely off balance. Unfortunately, once you’ve done that, it can take quite a while to get your rhythm back so you can get a good night’s sleep once again. The really strange news, however, is that your alarm clock may even be one of the culprits keeping you up nights.
Shift work is a reality of our modern economy. Services don’t stop running when the sun goes down. Without night workers—nurses and doctors, toll booth workers, security guards, policemen and women, truck drivers, pilots, and more—our world would grind to a halt. One of my closest friends works nights at a home for children. Most of his time is spent reading, but when the kids wake up or there’s an emergency, he is the first person on the scene. Without him, those kids wouldn’t be safe. But he pays a high price. Like many late shift workers, he suffers from terrible sleep-wake disruption, and is always either strung out or exhausted. After years of this strange schedule, he suffers from a host of physical problems. He has high blood pressure, struggles with his weight, and was just diagnosed with type 2 diabetes. He also has a lot of trouble with his relationship.
Human beings are built to respond to the natural light and dark cycle of the day. It makes sense that we would have evolved this way. After all, unlike cats, our eyes aren’t equipped to see very well in the dark. So, we had to do our hunting in the daytime and, the earlier we started looking for food, the more food we’d find before the day was over. As a consequence, our brains are more alert during daytime hours. As the sun sets, we start to slow down. Even if you consider yourself a night person, your productivity still wanes with the loss of daylight. Of course, nowadays we are surrounded by artificial light. It makes sense that this light might wreak some havoc on our sleep/wake patterns.