disabilities, and psychological or behavioral disorders. Bladder instability Urodynamic sleep studies show that enuretic children have high pressure bladder contractions more frequently while they are asleep when compared to healthy children. Nocturnal polyuria and antidiuretic hormone secretion Nocturnal polyuria is defined as having more than 130% of the expected bladder capacity, which is specific for each age. Many children with nocturnal enuresis have altered nighttime secretion levels of antidiuretic hormone, which controls water retention in the body. This results in low antidiuretic hormone levels and excessive amounts of urine produced during sleep time. Sleep disorders The inability to wake from sleep has been understood as one cause of nocturnal enuresis, however studies focused on the importance of the time of night in which enuresis episodes occur have shown inconsistent results. Parents often report that their bedwetting children are very difficult to awaken from sleep, therefore research regarding enuresis has also aimed to elucidate why children with enuresis do not awaken from the sensation of a full bladder. Some studies have led to hypotheses that children with enuresis have altered hemodynamics during sleep (in terms of measurements of blood pressure and heart rate), sleep-disordered breathing, and altered hypothalamus function leading to a lack of bladder control during sleep. Genetics Enuresis is also theorized to be a hereditary condition based on epidemiological and genetic studies. Although several genes are considered of interest in relation to enuresis, lack of a single gene that may cause enuresis means that individuals of a family may have differing genetic mechanisms resulting in the condition. Pathophysiology Currently, nocturnal enuresis is understood to be caused by three main underlying factors: excess urine production at night, lack of capacity for bladder storage, and inability to wake from sleep, with pathogenesis possibly varying based on presence of daytime symptoms. The inability to control the detrusor muscle has been theorized as a possible pathophysiological cause of enuresis, which may explain why anticholinergic drugs are effective as medication therapy, since they act on the detrusor muscles. Diagnosis Clinical definition of enuresis is urinary incontinence beyond age of 4 years for daytime and beyond 6 years for nighttime, or loss of continence after three months of dryness. Current DSM-5 criteria: Repeated voiding of urine into bed or clothes (whether involuntary or intentional) Behavior must be clinically significant as manifested by either a frequency of twice a week for at least three consecutive months