Tossing and turning all night long? Staring at the ceiling for hours, praying that sleep will come?

If you are one of the more than 100 million Americans who suffer from insomnia, sleep may be what you crave the most in your life.

“There is a whole field called ‘sleep hygiene,’ ” said Dr. David Rapoport, associate professor of medicine at the New York University School of Medicine and director of the school’s Sleep Medicine Program. “Sleep is a habit, so that’s where you have to start. If you foster bad habits, it’s harder to get out of bad sleep hygiene or insomnia.”

First, decide if something is medically or physically preventing you from sleeping, Rapoport said. If you have a medical disorder, no amount of effort on your part will help you sleep better.

This could include medical conditions, frequent pain or be the result of medication. For example, beta blockers, which are used to control blood pressure, can cause nightmares, and antidepressants can have an effect on the dream period of sleep known as rapid eye movement, Rapoport said.

If you are physically healthy and are still having a hard time falling asleep, Rapoport suggests trying these sleep habits:

1. Leave Your Worries Behind

Or at least don’t bring them to bed with you.

“Set aside some time when you are not in bed for worrying,” Rapoport said.

Rapoport suggested keeping a “worry” book, basically a pen and paper, by your bed so when you fall into worry mode, you can turn on your light and write down a list of things you need to worry about – the next day.

“It’s quite amazing how this works in certain cases,” he said.

2. Hide the Clock

Not literally, but sort of.

People who stare at their alarm clock every few minutes should turn it around, Rapoport said, so that they can't see it but will still hear it in the morning.

“If you are thinking, ‘it’s 2:10 a.m., it’s 2:15 a.m., what am I going to do?' that’s a sure-fire recipe for disaster,” Rapoport said. “Turn the clock away so you can’t see it, and when the alarm goes off, you’ll get up. You’ll fall asleep when you fall asleep, but don’t worry about it in the meantime. If you wake up in the middle of the night, that’s normal.”

The difference between an insomniac and someone who isn’t? The insomniac worries about the clock, Rapoport said.

3. Keep a Regular Schedule

Your body is programmed to sleep at certain times — usually when it is dark outside.

So it also makes sense that your body desires a regular sleeping schedule, Rapoport said.

If you are partying on the weekends, staying up until 4 a.m., but trying to go to bed at 11 p.m. on weeknights, your body is going to be confused.

“Don’t drastically change your bedtime from weeknights to weekends,” Rapoport said. “If on Friday and Saturday you are staying up all night, on Sunday your body is expecting to do that, and on Monday morning it will be hard to get up.”

4. Relax

Avoid stress-inducing habits before going to sleep. These include anything that may get your pulse beating faster, such as watching the news, reading an intense book, exercising, responding to e-mail and drinking caffeine, Rapoport said.

If you want to read, try lighter material like a fashion or sports-themed magazine.

5. Rx Fix

If you are going to use an oral sleep aid, Rapoport suggests talking to your health care provider about taking a prescription sleep aid as they work better than over-the-counter pills.

“If you absolutely need medicine, you are better off getting a prescription,” he said. “There is a new class of sleeping pills that are very safe and when used properly are effective.”

These medicines, like Ambien or Lunesta, are designed to help people sleep for a desired amount of hours and wake up feeling well-rested, Rapoport said.

Other sleep aids, like over-the-counter pills, or even wine, can suppress certain stages of sleep, Rapoport said.