SEE A DOCTOR WHEN ITS TIME TO GET HELP SLEEPING

More than 70 sleep disorders have been identified, said Dr. Bradley K. Bittle, a Cape Girardeau sleep specialist, but most of those are "reasonably rare."

Sleep disorders run the gamut from insomnia -- the inability to fall asleep -- to hypersomnia -- feeling sleepy all the time -- to narcolepsy, or "sleep attacks."

Restless leg disorder -- a burning or tingling sensation in the legs that occurs when sufferers hit the hay for the night -- is fairly common, and can be treated with medication. Periodic limb movement disorder, or jerking of the legs during the night, can wake sleepers up several times during the night.

Parasomnias are sleep disorders such as sleepwalking, sleep talking, sleep terrors and REM movement disorder, in which sleepers actually act out their dreams. REM movement disorder is most common in older men, and if they're having violent dreams, can result in injuries to them or their bedmates.

Everyone has a sleepless night now and then, and there's nothing more frustrating than tossing and turning all night. There are a number of causes for sleeplessness, from apneas or breathing obstructions to physical and emotional stresses. When doctors take patient histories, their questions cover everything from sleep habits to patients' emotional states, Bittle said.

And some people, he said, "have trained themselves to not fall asleep in bed." They may doze off in the recliner in front of the TV, but once they get to bed, they worry themselves into a wide-awake state.

It's time to get help if you find yourself dozing off at work or at the wheel while driving or operating heavy equipment. Long-term sleeplessness and fatigue can be life-threatening and can aggravate chronic health problems like diabetes and high blood pressure. If you always feel tired or if you think you aren't sleeping, see your family physician, who may refer you to a sleep specialist for testing.

Here are some tips to make drifting off to dreamland easier:

-- Maintain a regular bedtime and wakeup schedule. Going to bed and getting up at the same time every day keeps your biological clock in sync.

-- Exercise enhances sleep by letting off tension, but if you exercise too late in the day, your sleep will probably be disturbed. Regular late afternoon (around 4 p.m.) exercise promotes the best sleep.

-- Cut down on stimulants known to disturb sleep, including coffee, cola, chocolate and nicotine. Caffeine peaks in two to four hours, and smokers shouldn't puff within three hours of bedtime, because nicotine is an even stronger stimulant than caffeine.

-- Invest in a good mattress. You spend a third of your life in bed, so quality bedding makes sense.

-- Don't go to bed too hungry or too full. Meals heavy in protein and fats send your digestive system into overdrive, which keeps you awake, and an empty stomach will also disrupt sleep. Milk has sedative effects, and so do carbohydrates and fruits.

-- Watch the thermostat. The ideal sleep temperature is 65 to 68 degrees. At a temperature above 75 degrees, REM sleep, or the deepest sleep stage, will be disrupted. At temperatures below 60, dreams become more emotional.

-- A warm bath and quiet reading half an hour before bedtime really helps you relax.

-- Naps aren't recommended during the day, because when bedtime comes, your body won't feel the need for sleep. Older people should limit naps to an hour a day and take them at the same time every day.