Nocturnal enuresis, defined as involuntary bedwetting at least twice weekly in children five years and older,¹ affects 15% to 20% of children by five years of age.² Children with enuresis have lower self-esteem, lower self-confidence, and decreased quality of life compared with children who do not have enuresis.^3,4 Each year, 14% of children will experience spontaneous resolution, with sharp decreases in incidence among older children (1% to 2% by 17 years of age) and adults (0.5% to 1%), according to cross-sectional data.² Severe enuresis (nightly, heavy wetting or daytime symptoms) is less likely to resolve spontaneously; early intervention is key to resolution.⁵ Treatment improves patients’ health-related quality of life scores, including self-esteem, emotional well-being, and relationships with friends and family.⁶ Familial disposition is the biggest risk factor for enuresis; children from families without a history of enuresis have an incidence of 15%, whereas children from families with a history of enuresis have a 44% and 77% likelihood of developing enuresis if one or both parents were enuretic, respectively.² Enuresis tends to resolve in first-degree relatives at similar ages.^1,7,8 Additional risk factors for nocturnal enuresis are listed in Table 1.^9,10 This article addresses common questions about nocturnal enuresis.

What Is the Difference Between Monosymptomatic and Nonmonosymptomatic Nocturnal Enuresis?

Nocturnal enuresis can be divided into two subtypes: monosymptomatic, in which nighttime bedwetting is the only symptom, and nonmonosymptomatic enuresis, which includes the presence of daytime lower urinary tract symptoms with bedwetting¹ (Table 2^1,11). Monosymptomatic nocturnal enuresis can be subdivided into primary monosymptomatic nocturnal enuresis, where there has never been six months of continuous dry nights, and secondary monosymptomatic nocturnal enuresis, where a period of six months of continuous nighttime dryness existed and then bedwetting recurred.¹

EVIDENCE SUMMARY

Primary monosymptomatic nocturnal enuresis may be attributed to sleep arousal disorder, nocturnal polyuria, low bladder storage capacity, or detrusor overactivity. Children with sleep arousal disorders have a harder time waking in response to normal bladder cues. These children have more fragmented and nonrestorative sleep.^12–14 Nocturnal polyuria and large volume voids are present when the kidneys do not concentrate urine appropriately. The formal evaluation of polyuria includes weighing sheets or diapers and measuring the first-morning void volume. Factors contributing to polyuria include drinking large volumes before bedtime; ingestion of large amounts of solute, such as salt or sugar; and decreased vasopressin release from the pituitary at night.¹ Underlying bladder issues, including low bladder storage capacity and detrusor overactivity, may also cause enuresis.¹ Secondary monosymptomatic nocturnal enuresis is more likely to have an underlying pathologic cause and may be the first sign of a new medical issue. Common causes of secondary monosymptomatic nocturnal enuresis² are listed in Table 3.^1,15,16

Nonmonosymptomatic nocturnal enuresis occurs in 15% to 30% of children with enuresis.¹⁷ It is usually attributed to an underlying pathologic cause; common causes are listed in Table 4.^1,17 Diagnosis and treatment of the underlying pathology causing the daytime symptoms should occur before nocturnal enuresis therapy.¹⁷ Children with nonmonosymptomatic nocturnal enuresis have a higher incidence of comorbid psychological disorders, including attention-deficit/hyperactivity disorder, conduct disorder, developmental delay, oppositional defiant disorder, and separation anxiety.^17–20