• Involuntary, urinary incontinence after age of expected bladder control; term generally reserved for children ≥5 years of age; may be
    • Primary: has never been “dry” for 6 months (80%)
    • Secondary: patient previously “dry” for 6 months or longer
  • Classified as
    • Monosymptomatic nocturnal enuresis (MNE)
    • Non-monosymptomatic nocturnal enuresis (NMNE) if there is evidence of lower urinary tract malfunction (e.g., delayed voiding, frequency, urgency, holding maneuvers)


  • Male > female, although some recent reports state that nocturnal enuresis is more common in girls than in boys
  • Prevalence
    • 10–15% of children at age 5 years
    • 7–15% of children at 7 years
    • 5% of children at 10 years
    • 0.5–1% in teenagers and adults

Risk Factors

  • Constipation
  • Lower urinary tract dysfunction
  • Sleep disorders (e.g., obstructive sleep apnea [OSA])
  • Neuropsychiatric disorders


  • 60–70% have a positive family history of enuresis.
  • Risk of severe enuresis is greater with maternal enuresis history compared with paternal history (odds ratio 3.6 vs. 1.8).
  • Autosomal dominant pattern seen in 50%, whereas 30% of cases are sporadic
  • Risk is twice as high in monozygotic twin of a child with enuresis compared with a dizygotic twin.
  • Several loci on chromosomes 8q, 12q, 13q, and 22q associated with a nocturnal enuresis phenotype; candidate genes include ENUR1 and ENUR2.


  • Primary nocturnal enuresis: results from interplay of one or more of the following:
    • Nocturnal polyuria
    • Decreased functional bladder volume
    • Increased detrusor activity
    • Increased arousal threshold when asleep
    • Inadequate secretion of antidiuretic hormone
  • Daytime incontinence and enuresis, day and night
    • As above
    • More concerning for underlying urologic and neurologic disorder
    • Urinary reflux into vagina with seepage after conclusion of voiding
    • Insertion of ureter into urethra or vagina
    • Stress incontinence with increased abdominal pressure (laughing, coughing, increased intravesicular pressure)
  • Secondary enuresis can result from:
    • Any condition causing polyuria (including diabetes, hypercalcemia)
    • Urinary tract infection (UTI)
    • Encopresis
    • Emotional stress or trauma including physical and sexual abuse, parental divorce, depression, new sibling, household moving, new school

Commonly Associated Conditions

Neuropsychiatric comorbidities: ADHD, anxiety, and oppositional behavior are more commonly associated with secondary nocturnal enuresis.

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