Primary enuresis (comprising 80% of cases) is diagnosed when urinary continence has not been established for 6 months. There are also other categories : Nocturnal enuresis occurs during sleep only, whereas diurnal enuresis occurs when the child is awake. Monosymptomatic or uncomplicated enuresis refers to nocturnal enuresis where there are no identified urinary tract problems.
Shreeram et al. believed the range of prevalence estimates(3.8% to 24%) is due in part to different definitions of enuresis. They noted that studies have also lacked structured clinical interviews