Also known as bedwetting, the inability to control urination during periods of sleep.

Sometime around the age of three, children typically begin to exhibit bladder control during the day and make the transition from diapers to toileting. For most children, nighttime bladder control follows. The term enuresis—often thought of as the technical term for bedwetting—refers to the continued involuntary passage of urine after an age at which control is expected.

When daytime wetting persists beyond the age of four, or nighttime wetting persists beyond the age of six, the child is considered to have primary enuresis. When the ability to stay dry has developed normally and without intervention but is followed by a period of wetting that lasts for three months or more, the child is considered to have secondary enuresis. The distinction between these two types is based on the child's physiological ability to control...