A woman distractedly puts a pile of dirty dishes in the refrigerator and the leftover roast in the dishwasher.

A piano teacher is so restless she cannot sit still through a lesson, but must get up and walk around the room several times while her pupils are playing.

A middle-aged man whose wife complains of his snoring falls out of bed.

A woman tells her physician sadly that she can no longer . . . laugh. She wants to -- it's not that things don't strike her funny -- but whenever she's about to, she falls down.

These are all real cases. And they all have a common thread that in each case leads to sleep. Or rather, a disorder of sleep.

Ten years ago or five, or even today, sleep as a major element -- or as the major element -- in this sort of bizarre behavior was likely to be missed. Patients were shunted from psychiatrist to psychiatrist, usually without being helped.

It took scientists a good while to wake up to the mysteries of sleep. And although the field is still relatively new, still relatively mysterious and many of the disorders still without easy solutions, the knowledge about what we do during that approximately one-third of our lives in which we are sleeping -- or tossing and turning -- is burgeoning.

In fact, many of the sleep specialists -- physicians and researchers -- are eager to disseminate some of their new knowledge to general practitioners.

Project Sleep, a three-year national program established in 1980, determined that a whopping 93 percent of American medical schools were deficient in how they taught students about sleep and its problems. Dr. J. Stephen Kennedy, Sleep's director, says that the project's most important accomplishment has been the creation of a "sleep curriculum" for use by medical schools and in continuing education programs.

Project Sleep also has focused public awareness on the complicated nature of night's most natural and ubiquitous event.

Says Kennedy, "Ask everybody in the country if they have a sleep problem and practically everybody will say 'yes.' Then ask, 'Oh come on, we're talking about a really serious sleep problem' -- and you'd still get a yes from about 30 million people . . ."

Dr. Stephen Targum, director of Research and Evaluation for the Psychiatric Institute of Washington, D.C., puts it this way:

"In some ways, sleep disturbances are universal, and perhaps it is 100 percent. If you don't have difficulty falling asleep, you have difficulty getting up in the morning or being drowsy during the day. Everyone's experienced in some way, one form or another, a sleep disturbance . . . yet it is of growing concern that the medical community has not focused on sleep as a particular problem . . ."

At a recent day-long seminar for health professionals sponsored here by the Psychiatric Institute Foundation, some of the nation's top sleep scientists made a state-of-the-art presentation--outlining the disorders so-far identified and various therapeutic approaches.

Of some 30,000 letters received by Project Sleep, the two most prevalent categories were from the elderly and from people with psychiatric disorders.

This is no great surprise to the sleep specialists; they have identified clear psychobiological links between medical depressions, some other mental illnesses and sleep disorders.

And they have determined that it is not necessarily normal for older people to sleep less. It is more likely that the elderly are simply more prone to disorders of sleep or to others, such as painful arthritis, that interfere with sleep.

The unhappy problem is, however, that even when sleep disorders are diagnosed properly, there is no universal cure; there are a variety of approaches to many of the growing list of sleep-related disorders, but no perfect answers to any.

Although 25 million Americans spend more than $200 million dollars a year on sleeping medicines, the scientists agree that in the vast majority of cases no sleeping pill -- whether expensive prescription or over-the-counter nostrum -- should be used except occasionally and only for a few days at a time. Pills may put you "out," but being "out" may not be the same as being "asleep."

Sleep is the natural way our bodies recharge, restore, rejuvenate, refresh. Drugs can affect the stages of sleep, and, some specialists speculate, may block some or all of the restorative functions that occur normally. Moreover, most of the stronger drugs, including the popular flurazepane (Dalmane) have effects that go on well into the next day, affecting performance by dulling reflexes, clouding thought, stultifying creativity.

There is a real place for drug therapy, however, for some sleep problems, some of the time -- especially when they are linked to mental problems, such as depression. But dependence on sleeping medicines night after night, for months at a time, is not the way to a good night's rest. Drug dependence, in fact, is eventually counter-productive, and often produces serious withdrawal symptoms -- including worsened insomnia -- when the medication is halted.

Dr. Wallace Mendelson, director of the Sleep Unit of the National Institute of Mental Health, and a well-known authority and author on sleeping pills and sleep (The Use and Misuse of Sleeping Pills, Plenum Medical Book Co.) and Dr. Richard Allen, co-director of the Baltimore Sleep Disorders Center, each warn about the use of sedatives or hypnotics, especially in older patients.

Allen notes that in the surveys conducted by Project Sleep more than half of the over-65 population complained of serious sleep problems. Sleeping pills are second only to cardiovascular medicines in usage among the elderly.

In addition, he says, "Maybe 40 percent of normal, noncomplaining elderly people suffer from a disorder that causes many arousals throughout the night plus daytime sleepiness," because of brief but repeated breathing stoppages. Drugs can make it worse -- even with potentially fatal results.

Mendelson notes that the class of drugs that includes Valium, Librium and Dalmane are "extremely long acting--50 to 100 hours. If you take one Dalmane nightly, you will have accumulated about 7 times the normal dose after two weeks. Moreover," he says, "people who know better than to take a sleeping pill and an alcoholic drink together might not realize that if they take the pill and 18 hours later have a drink, they are still mixing a sleeping pill with alcohol."

Sleep disorders have been divided into a number of classes, with some 65 distinct sleep dysfunctions identified. More than half the people who seek help from sleep specialists complain of hypersomnia -- "inappropriate and undesirable sleepiness during waking hours," often apparently unrelated to the amount of sleep they get at night.

The piano teacher who couldn't sit still was suffering from a disorder called myoclonus. She was, without realizing it, being wakened 300 to 400 times a night by spontaneous muscle spasms. Her so-called "restless leg syndrome" during the day was a major tip-off to a sleep specialist.

The man who fell out of bed was suffering from obstructive sleep apnea, once thought to affect some 50,000 mostly middle-aged, overweight men, but now believed much more prevalent, with up to a million sufferers. In this disorder, breathing can stop at the height of a snore when the upper airway walls briefly collapse in on themselves, blocking air. Breathing resumes after as long as half a minute, with a noisy snort. The sufferer often wakes with a transient headache and falls asleep at inappropriate moments during the day, causing major marital or work-related problems.

In its most serious form, apnea is a potentially lethal ailment, causing hypertension, deprivation of oxygen to the brain and even suffocation. Surgery and an assortment of devices to be worn at night are among some of the not altogether satisfactory treatments, except in extreme cases.

The woman who washed her roast and the one who couldn't laugh were both suffering from forms of narcolepsy -- uncontrollable daytime sleep episodes. In some patients, there is an associated disorder called cataplexy, seconds-long episodes of muscle weakness or paralysis. For reasons that are as yet unknown, these are usually brought on by strong emotions, especially laughter or anger.

Dr. Merrill Mitler, a specialist in these disorders at State University of New York at Stonybrook, says scientists learned much about the disorder because it afflicts large dogs, like Labrador retrievers and Dobermans, much as it afflicts humans. At the moment, treatment for narcolepsy and cataplexy "is a lifelong series of trials with stimulus medications," says Mitler, but at least its victims, by the very diagno- sis, can be free of the stigma.

Children have special sleep problems including sleep walking, bedwetting and night terrors in which the child inexplicably wakes screaming and inconsolable, yet without having had a bad dream. Other adult problems grow out of disturbances of circadian rhythms: the cycles "circa-a-day" by which most creatures on this planet function. Jet lag is one; switching shifts on a job is another.

Cures, even treatments, are only in preliminary stages in the country's approximately 75 accredited and partially accredited sleep centers, but at least the specialists know now that sleep is a lot more than just the absence of wakefulness. And a sleep disorder doesn't just affect the night. CAPTION: Picture, Illustration, From "Dr. Seuss's Sleep Book," Copyright(c) 1962 by Dr. Seuss. Reprinted by permission of Random House Inc.