Infant, toddler, or teen, most kids experience a sleep problem at one time or another. Here are surefire new solutions to the most common ones.

As much as you want to go to sleep, your baby wants to stay up. And as most parents know, the baby (and, later, the child) has the edge. What can you do to tilt the odds in your favor? Experts say that if you understand why children have trouble falling and staying asleep, you can teach them the skills they need to nod off peacefully. That's particularly important because they're likely to carry the sleep habits they develop now into adulthood.

Through their teens kids may need nine to 12 hours of sleep a day. Researchers believe that it helps restore a child's body, which is growing and changing rapidly. Because a youngster's brain is still developing, however, the transitions between deep non-REM and lighter REM sleep stages (when people dream) aren't always as smooth and quick as they are in adults. Young children may waken enough to be aware of their surroundings several times a night. That's when they stir, cry, or exhibit certain sleep disturbances.

Experts agree that there are no absolute rules for the best way to get kids to go to sleep and stay asleep. "If you don't mind getting up a couple of times a night during the early years to hold or soothe your child when he awakens, there's no reason not to," says Barry Zuckerman, M.D., F.A.A.P., professor and chairman of pediatrics at Boston University School of Medicine. But this routine might continue until school age. "You need a new strategy when yours isn't working for you, or when your child isn't getting the rest he needs."

Here's what to expect at different ages

Some babies mix up their nights and days--sleeping all day and ready for play after the 2:00 A.M. feeding. The best way to turn a newborn around is to be as dull as possible during nighttime interactions. Feed and change her, but do so without talking or singing in an animated voice, and in low light, if any. Then put her back to bed. During the day, take the opposite tack. Try to lengthen the alert periods by playing with your newborn rather than putting her immediately back in the crib or baby seat after each feeding, or handing her a pacifier--which tends to induce sleepiness. Some babies take only a few days to turn around; others take weeks.

Babies are now capable of sleeping for longer periods at night without a feeding, often six to eight hours between 10:00 P.M. and 6:00 A.M. Yet many either still take an occasional feeding at night or wake up and need attention. Pediatricians feel that in most cases these sleep disturbances are actually fostered by parents' habits. Sometimes parents think their babies are waking up when they're really going through a light slumber phase.

Hearing the baby's whimpering or crying as he puts himself back to sleep, parents assume he's in distress. "They rush in to reassure the baby unnecessarily and actually interrupt his sleep," says S. Norman Sherry, M.D., F.A.A.P., assistant clinical professor of pediatrics at Harvard Medical School. "Give your baby a few minutes to settle himself before going in to soothe him."

At this age, when the crying goes on for longer than a few minutes, the problem is usually connected to the position in which the baby routinely goes to sleep. "If a baby is used to falling asleep while in her parent's arms, either breast-feeding or taking a bottle," says Barry Zuckerman, M.D., F.A.A.P., professor and chairman of pediatrics at Boston University School of Medicine, "She may not be able to put herself back to sleep after the frequent semiarousals at night unless she's back in her arms again."

Richard Ferber, M.D., F.A.A.P., author of Solve Your Child's Sleep Problems and director of the Center for Pediatric Sleep Disorders at Children's Hospital in Boston, is famous for his "Ferberizing" technique, which parents can use to help their children get themselves to sleep. It involves putting an infant to bed while still drowsy, and if the baby cries, gradually extending the periods before you go back to comfort him (with a brief pat on the back and soothing words--not picking up or cuddling). Babies accustomed to falling asleep in someone's arms don't like this, so there's almost always some heartbreaking crying that goes along with this retraining. But pediatricians believe that the short period of crying won't hurt the baby--in fact, some babies may even need to cry to let off steam before snoozing. After a few days, the baby will find ways of putting herself to sleep--sucking a thumb or rooting around in the crib or some other comforting behavior.

Parents needn't be too rigid about adhering to this method once they've started it. "If a child is sick or frightened, it's your responsibility to give that child whatever he or she needs--even if you have to make some temporary changes in the normal sleep routine," says Dr. Ferber. "From day one, the most important thing is for your child to know that she's been born into a loving, caring universe where needs are going to be met."

What about babies who still need a bottle or two in the middle of the night? "More often than not, a six-month-old appears to be hungry twice a night because he's fed twice a night," says Dr. Ferber. "If you don't mind getting up, there's no problem. But if you do, the way to stop the night feedings is to gradually space them out until the baby gets used to going a full night without one."

Other problems, such as stomach cramps or other pains, are not as easy to pinpoint. The important thing to note is that no pediatrician suggests letting your child cry for hours on end night after night.

Some toddlers who have been sound sleepers start to wake and cry for company at this age. "The problem has less to do with how they fall asleep and more with separation anxiety," says S. Norman Sherry, M.D., F.A.A.P., assistant clinical professor of pediatrics at Harvard Medical School. "One way to get a child to comfort himself at night is to help him develop a transitional object that will take your place." You can encourage your child's attachment to the blanket, doll, or stuffed animal by making it a part of the nighttime ritual. Then when he wakes in the wee hours, he can snuggle with his "lovey" for comfort.

At this age, the fierce desire for autonomy and strong curiosity are what make bedtime a battle. "Children are striving for control now," says Barry Zuckerman, M.D., F.A.A.P., professor and chairman of pediatrics at Boston University School of Medicine. "A nighttime ritual that they dictate addresses that need and ends the bedtime fights." Let your child decide, for instance, what pajamas to wear, or whether to bathe or hear a story first.

Other sleep-associated behaviors that begin at this time:

Rocking, chanting, and head-banging are habits young children often use to get themselves to sleep. Head-banging is particularly disconcerting to parents, but experts say that children don't hit their heads hard enough to hurt themselves.

Nightmares can be allayed with your soothing words and presence until the child falls back asleep. You can also establish rituals such as turning the pillow over to the "good dream" side or brushing away nightmares from the pillow.

Night terrors are upsetting to parents not only because the half-awake youngster clearly appears terrified by something--and screams or thrashes around--but also because he appears not to recognize the parents and will push them away. It's best to let this run its course for the ten to 30 minutes it lasts, though you can make reassuring comments like, "You're safe. Mommy's here."

Once a child reaches school age, most bedtime problems will be a memory. However, nightmares and sleepwalking may still be common in the first few years.

During sleepwalking the child may seem to be awake: Eyes may be open, she may murmur and walk around. Sometimes she'll allow you to guide her back to bed or go there by herself if she's told to. If she resists, it's best to let the episode play itself out until she awakens. Gates across stairwells are recommended to prevent falls.

If nightmares or sleepwalking starts to occur more often, or if either or both of these conditions begin in older years when they never happened before, psychological factors may be a cause. You'll want to talk to your child to see if he or she is disturbed or anxious about something.

By this stage, the problem that can interfere with a child's sleep more often than not is a daily schedule so full it doesn't leave enough room for the rest that's needed. There's a myth that teens, full of youthful energy, don't need a lot of sleep. But, says Richard Ferber, M.D., F.A.A.P., author of Solve Your Child's Sleep Problems and director of the Center for Pediatric Sleep Disorders at Children's Hospital in Boston, "teens are still developing and need a solid eight or nine hours every night."

If your child suffers insomnia, anxieties may be keeping him up. A talk with you or the pediatrician may be all that's needed to address the problem, but if the distress continues, the doctor may feel that further counseling is necessary and want to refer your child to a specialist.

Some teens, on the other hand, seem to sleep all the time--late on school days and most of the weekend. If this lethargy is accompanied by a loss of interest in school and social activities, it might indicate depression, and you should bring these symptoms to your pediatrician's attention as well.