When you were a kid, you may not have been able to go sleep at night without a night light. Somehow that tiny bulb kept away the monsters in your closet and other scary things lurking in the dark. These days, you may still be afraid of the dark—but for a very different reason: not being able to sleep. And this fear seems perfectly rational considering how many mornings you pry your tired self out of bed and how many afternoons you spend yawning and rubbing your bleary eyes. And judging from your friends’ Facebook status updates at all hours of the night (or is it morning?), you’re not alone.

“At least 40 million Americans suffer from some form of insomnia, the inability to fall asleep or stay asleep, but it’s probably more than that because many don’t report it,” says Eric Plasker, a wellness expert. “Everyone has one sleepless night here and there. But if you are wondering if you have a problem sleeping, then you probably do.”

The good news is that many causes behind sleepless nights are as easily eradicated as those fears of monsters in the closet. You just need to shine a little light on them.

MONSTER IN THE CLOSET:
Snuggling up with technology
SHINE SOME LIGHT ON IT: How often do you bring your laptop to bed to finish up a few last-minute slides for tomorrow’s presentation? Do you find yourself checking your BlackBerry when you get up for a drink of water at 3 a.m.? Are you in the habit of watching the local news right before turning out the lights? If this sounds familiar, technology is interfering with the sanctity of your bedroom.

“The bedroom is a sleeping place, an escape,” Plasker says. “Don’t bring the intensity of life into bed. Watching the news or action-based shows or reading a suspense novel before bed causes tension and gets your heart racing. And leave your BlackBerry in another room. Your spam can wait.”

MONSTER IN THE CLOSET:
Traveling to new time zones
SHINE SOME LIGHT ON IT: Whether you’re a casual vacation-only traveler or a member of every airline’s corporate flier program, jet lag can challenge your sleep cycle. Studies have shown that the condition results from an imbalance in our body’s natural 24-hour cycle, or circadian rhythms, according to the National Sleep Foundation (NSF).

When we switch time zones, our circadian rhythms can take several days to adjust. To help combat jet lag, the NSF recommends selecting a flight that allows early evening arrival and staying up until 10 p.m. local time. For longer trips, anticipating the time change by going to bed and getting up earlier several days prior to an eastward excursion and later for a westward trip can help. Also, while you are away, try to get outside in the sunlight whenever possible to help regulate your biological clock.

MONSTER IN THE CLOSET:
Jonesing for java
SHINE SOME LIGHT ON IT: On any given day, about 85 percent of Americans use caffeine products, according to estimates by the American Academy of Sleep Medicine (AASM). But at what cost?

“When we aren’t getting enough sleep, we try stimulants like coffee and energy drinks,” says Stephen L. Newman, M.D., a spokesman for the AASM. “That can perpetuate insomnia.” In fact, you may end up in a vicious cycle of consuming caffeine during the day to stay awake, but then finding it difficult to fall asleep at night because of all the caffeine you’ve ingested.

And while a normal cup of coffee in 1980 was 6 ounces, now a “tall”—which is Starbucks lingo for “small”—is 12 ounces, Newman says. That means your “small cup of coffee” is actually two. So watch your trips to the coffeepot: The AASM recommends limiting your caffeine consumption to about 300 milligrams to 400 milligrams per day (three to four 8-ounce cups of coffee) and avoiding it altogether in the late afternoon and evening. Newman, however, offers his own recommendation: “Cut down on or eliminate caffeine from your life altogether. You’ll sleep a heck of a lot better.”

MONSTER IN THE CLOSET:
Excess weight
SHINE SOME LIGHT ON IT: While lugging around extra pounds during the day is exhausting enough, trying to find a restful position at night is equally arduous.

“Being overweight affects your breathing and makes it hard to get comfortable,” says Plasker, who recommends exercise to lose that extra heft and also to sleep better. “Exercise not only helps you burn calories, but it increases your metabolism and makes you tired. Working out in the morning is best, but just doing it is important.” So if your schedule is such that you have to exercise at night, that’s fine, but Plasker recommends finishing two hours before bedtime.

MONSTER IN THE CLOSET:
Succumbing to stress
SHINE SOME LIGHT ON IT: Who isn’t stressed these days? Between unemployment or a hectic job, financial troubles, difficult relationships, needy kids, aging parents and never-ending household chores, you’re under a lot of pressure. Even if you can find the time to sleep, that doesn’t mean you can clear your head and actually catch some ZZZs.

“If people don’t manage stress, it can affect their sleep,” Plasker says. “It keeps them up at night or wakes them up in the middle of the night.” To help overcome stress, he suggests trying such bedtime rituals as listening to relaxing music, focusing on deep breathing (in for two counts and out for four) to slow your heart rate and reduce muscle tension, and keeping a journal by your bed to write down thoughts that keep you up.

“There’s something about taking those thoughts out of your head and putting them on paper that helps rest your mind. You know the thoughts will be there in the morning,” he says.

MONSTER IN THE CLOSET:
Sleeping in unsavory conditions
SHINE SOME LIGHT ON IT: You’re hot. You’re cold. Your mattress is too firm. Or is it too soft? Your pillow needs fluffing. If trying to fall asleep makes you feel like Goldilocks, then fine-tuning your sleep hygiene with the following tips from the Better Sleep Council could make your sleep environment just right.

First, transform your bedroom into a haven of comfort that is dark, quiet and cool. Next, evaluate your mattress and pillow to ensure proper comfort and support. If your mattress is five to seven years old, it may be time for a new one; pillows should be replaced every year. Also, avoid alcohol and nicotine, as they can lead to a bad night’s sleep. Finally, create a bedtime routine that is relaxing, such as reading a peaceful book or soaking in a hot bath.