The medical community has long believed that children who wet the bed at night beyond the ages of 5 or 6 suffer from a sleep disorder. But recent studies have shown that sleep habits are no longer to blame.

Bedwetting, or enuresis, is often found in children who sleep very soundly, leading many to attribute its cause to sleep problems.

*Robin's 9-year-old son, *Brian, has been wetting the bed since he was a baby and she describes him as a very heavy sleeper. "He's like a rock when he's sound asleep," says the mother of two from Ft. Lauderdale, Fla. "He's deadweight. Sometimes he's sound asleep and will sleep right in [the urine]."

Dr. Mark Stein, chief of psychology and professor of psychiatry and pediatrics at Children's National Medical Center in Washington, D.C., explains that for many years enuresis was thought to be primarily a sleep disorder since children who wet the bed are often described as deep sleepers. "Controlled studies suggest that sleep problems or being a ‘deep sleeper' are not the primary cause of wetting," he says.

Studies on children with enuresis show that they have no unusual EEG patterns when sleeping, according to Dr. Frederick Kaskel, director of the division and training program in pediatric nephrology at the Albert Einstein College of Medicine in Bronx, N.Y. EEG, or electroencephalography, records the electrical activity of the brain through sensors attached to the head during sleep. Abnormal patterns appear in those with sleep disorders.

"Granted, some of them are deeper sleepers and need a little more arousal waking up," says Dr. Kaskel, who is also the chairperson of the Commission on Enuresis for the National Kidney Foundation. "This does not represent a true sleep disorder, just a variation from the norm."

So while Brian may sleep soundly, that's likely not the cause of his bedwetting, though it can exacerbate the problem.

So if not sleep, what does cause enuresis? Well, the jury's not back on that one yet, but there are a number of factors that likely contribute and when you mix them with a deep sleeper, you'll see how bedwetting often can result.

First, you need to understand that controlling urination is a complex process. It involves nerves, muscles, the spinal cord and the brain all working together. The bladder sends the brain a message when it's full that it's time to go to the bathroom, but if the person is asleep or not ready yet, the brain must keep the bladder from emptying. Sometimes, kids' bodies just don't have all of these pieces working in harmony quite yet.

"They just take a little longer to mature into this fully aware state so the brain can sense that they're getting full," says Dr. Kaskel.

Some children simply produce more urine or have a smaller bladder and in a small number of cases, a medical problem such as a kidney infection, diabetes or a blocked bladder can be to blame.

Bedwetting is also genetic. According to the National Kidney Foundation, if both parents were bedwetters, a child has a seven in 10 chance of wetting the bed. If one parent wet the bed as a child, then there is a four in 10 chance their children will do the same. Boys are also twice as likely as girls to wet the bed, according to the National Kidney and Urologic Diseases Information Clearinghouse, though experts do not know why.

For Brian, the cards just may be stacked against him, considering he's a deep sleeper, a boy and his mother says she also wet the bed as a child.

While bedwetting itself may not be a sleep disorder or the result of sleeping deeply, it can be a symptom of other sleep problems. For example, children with sleep apnea – characterized by loud and frequent snoring – often wet the bed.

Bedwetting also may accompany parasomnia, an arousal disorder where children may sleepwalk and have nightmares and night terrors. Arousal disorders occur when a child has difficulty coming out of a deep sleep before reaching the rapid eye movement (REM) or "dream" stage of sleep.

Retired pediatrician Dr. George Cohen disagrees with many experts about bedwetting's connection to sleep problems. He believes that like parasomnia, bedwetting can be an arousal disorder if it occurs during the first two or three hours of sleep. "When [children are] coming up out of a deep sleep, it seems not to be a smooth transition," says Dr. Cohen, editor of the American Academy of Pediatrics' book Guide to Your Child's Sleep. The difficult transition then manifests as a nightmare, wet bed or other problem.

The most important thing to realize about bedwetting, whether it's a sleep disorder or not, says Dr. Kaskel, is that there's nothing wrong with your child. It's simply beyond their control. Most experts recommend supportive, positive parenting and never reprimanding the child.

"The child cannot sense the urge while asleep and is not lazy or spiteful," says Dr. Kaskel. "The family unit must work together and not take out frustrations on the child. Abuse does happen this way, both physically and emotionally."

A first step in dealing with enuresis is to use disposable absorbent underpants while working on the problem. Absorbent underpants may help kids' self-esteem by alleviating the embarrassment of waking to cold, wet sheets and saving face in front of non-bedwetting siblings.

Treatments for enuresis range from moisture alarms to medication to the passing of time. If the wetting continues beyond age 5 or 6, you should first take your child to your pediatrician to rule out any medical problems. The doctor will then likely talk with you about your child's history of bedwetting and their sleep habits. Based on that information, he or she will then refer you to the most appropriate specialist – a urologist, a sleep specialist, a neurologist or a psychologist – if needed.

If all else fails, remember that bedwetting is something that most children outgrow. Says Dr. Kaskel, "eventually 99 percent will reach dryness with time."

* Names changed to protect privacy.