Bed-wetting is accidental urination during sleep. Accidental wetting (day or night) that develops or continues after a child is normally expected to have bladder control is called enuresis.

Accidental wetting of clothes or bedding is common in young children, because they develop bladder control at different rates. Most children are able to control their bladders and stop accidental wetting by 5 or 6 years of age.

A medical condition, such as a bladder infection or emotional stress, may cause accidental wetting that develops after a child has learned to control the bladder. In these cases, treatment or counseling may help stop the enuresis. If an older child still experiences enuresis and it is affecting the child's school performance or relationships with peers, treatment methods may involve a praise and reward system, a moisture alarm, or medicine.