Some children produce too much urine at night. These children may have low levels of a naturally occurring substance called vasopressin, which the brain normally produces during the night. Vasopressin reduces the amount of urine produced during the night and allows for uninterrupted sleep. This means that if the child has low levels of vasopressin at night, they may produce more urine than the bladder can hold. And if they do not wake up they may wet the bed.

Other causes of bedwetting

Bedwetting video For more information about how the bladder and the brain communicate and what goes wrong when children have difficulty rousing view the video: Causes of bedwetting- difficulty rousing from sleep.
Bedwetting video Learn how an overactive bladder can cause children to wet the bed by viewing the video: Causes of Bedwetting: Overactive or Twitchy Bladder.

More information on bedwetting

Bed Wetting For more information on Bedwetting, including risk factors, prevention and treatments, see Bed Wetting (Nocturnal Enuresis).