Nocturnal enuresis: why does your child pee in bed?

By Cristiano Antonino Last updated May 1, 2023

Widespread especially among children, nocturnal enuresis is the involuntary loss of urine during sleep (so much so that most people know it as ‘bedwetting’)

Sufferers include 5-10% of children under the age of 7 who occasionally wet the bed due to involuntary bladder emptying.

The disorder, in 3% of boys and 2% of girls, may continue until the age of 10.

The cause is generally attributable to a delay in the development of the ability to coordinate the voluntary muscles of urination.

In adults, nocturnal enuresis is, on the other hand, due to disorders of the urinary system, chronic illnesses (such as diabetes), stress and anxiety, or excessive consumption of caffeine, artificial colours or chocolate.

In this population group, we tend to speak of nocturnal incontinence.

Although it is not worrying, especially in children, it is a disorder that should not be underestimated and should be managed carefully and sensitively so that the child does not feel humiliated or frustrated.

Nocturnal enuresis: what is it?

Nocturnal enuresis is the involuntary loss of urine during the night.

It is typically suffered by children, who have not yet achieved the ability to coordinate the muscles innervated by the voluntary (somatic) and involuntary (vegetative) nervous systems that are responsible for controlling urination.

The ability to control urination is reached around 3 years of age, but there are children who develop it much earlier and others who reach full maturity around 8 years of age.

Nocturnal enuresis, in children up to 4/5 years of age, should not cause concern.

More attention is needed if the phenomenon continues after the age of five, for at least three months in a row and more than twice a week.

Nocturnal enuresis can be primary or secondary

The first, the most common, occurs when the child has never achieved control of urination during the night; the second, which affects about 20% of cases, occurs instead after a period in which the child (or the adult) has been able to control bladder capacity.

One also speaks of regressive enuresis, when a regression occurs typically caused by a traumatic event or a period of excessive stress.

This is a very different disorder from incontinence and pollakiuria.

The former consists of a constant loss of urine, day or night, typically caused by an injury to the central nervous system, the spinal cord or the nerves that manage the muscle fibres of the urinary tract; the latter involves very frequent urination due to metabolic, urinary or neuromuscular disorders or psychological problems.

The causes of nocturnal enuresis are different in children and adults

In children, the most frequent causes are

family predisposition: if one of the parents suffered from nocturnal enuresis, the child is 5 times more likely to suffer from it, if both parents suffered from it, the probability increases by 11 times;
difficulty waking up: the child cannot easily wake up during the night, even if the bladder is full;
reduced production of anti-diuretic hormone during the night: vasopressin (ADH) helps the kidneys reabsorb water and decreases the amount of urine produced during the night;
reduced bladder capacity in relation to age;
obstructive sleep apnoea: the interruption of breathing during sleep decreases oxygenation and the child finds it more difficult to experience a full bladder;
stressful events, such as fights between parents, the birth of a baby brother/sister or a big change;
urinary tract infection;
chronic constipation: the bladder becomes irritated due to irregular bowel movements, urination increases in frequency and the child’s ability to feel a full bladder decreases;
overactive bladder, a syndrome characterised by frequent urination (often associated with urinary incontinence);
diabetes mellitus: the child suffering from diabetes mellitus drinks a lot and urinates a lot even during the night (if he is always thirsty, urinates a lot and loses weight with a large appetite, the paediatrician should be consulted)
diabetes insipidus, a rare metabolic disease caused by insufficient secretion or reduced sensitivity of the kidneys to vasopressin;
anatomical abnormalities;
incorrect urination habits (e.g. the child does not empty the bladder completely when urinating);
obesity, which predisposes to diabetes and sleep disorders;
excessive fluid intake during the day or just before bedtime;
abuse of chocolate or other foods that stimulate diuresis, before going to bed.

As a rule, children suffering from this disorder are unable to wake up during the night when their bladder is full.

According to the latest studies, those with nocturnal enuresis have a poor quality of sleep, often have incomplete awakenings and move their arms and legs as if trying to get up without being able to do so.

The problem does not therefore lie in sleeping too deeply, as was previously believed.

In adults, nocturnal enuresis is typically caused by:

urinary tract infection;
diabetes;
use of sleeping pills or diuretics;
alcohol or coffee abuse;
stress or anxiety;
damage to the nerves that control the bladder muscles;
enlarged prostate gland;
sleep apnoea;
attention deficit hyperactivity disorder (ADHD).

If the adult has always suffered from nocturnal enuresis, he or she may produce an excessive amount of urine or have poor muscle or nerve control.

The symptoms

Nocturnal enuresis is manifested by the involuntary loss of urine during sleep.

Sometimes this symptom is accompanied by redness/irritation of the genitals and/or surrounding skin.

If the loss of urine also occurs while awake, we speak of mixed enuresis.

There are two types of nocturnal enuresis: monosymptomatic enuresis, which is not accompanied by urogenital or gastrointestinal symptoms, and polysymptomatic enuresis, which is associated with other symptoms.

When present, symptomatology may include:

frequent need to urinate
pain on urination;
constipation;
blood in the urine;
unexplained thirst;
fever;
encopresis (involuntary emission of faeces);
neurological problems;

Diagnosis

It is a good idea to take the child to the paediatrician, or to consult your doctor, in the event of frequent episodes of bed-wetting (at least twice a week, for three months in a row).

The child must be over five years old as enuresis, up to this age, is considered physiological.

In the adult, on the other hand, there must be psychological and social suffering caused by the disorder.

The diagnosis is essentially based on the anamnesis and an objective test.

The general practitioner, or urologist, inquires about the patient’s medical and family history and proceeds with a physical inspection of the genitals, abdomen, back, and spine.

He then performs a neurological examination and prescribes blood and urine tests to check for urinary tract infections and to rule out diabetes.

If necessary, an ultrasound of the urogenital system can be performed if a malformation or some other problem is suspected.

Up to the age of 5-6 years, enuresis is considered physiological.

In most cases, it resolves spontaneously, without the need for any treatment.

It is important not to punish, scold or humiliate the child.

In addition, talking to the paediatrician is essential because, although in most cases the disorder is not caused by a pathology, enuresis could still be due to an organic problem (and therefore resolve itself as soon as this is properly treated).

If the child is older than 5-6 years, the loss of urine during the night should be investigated.

Paediatricians often recommend keeping a urination diary, in which they note what time they pee during the day and night, whether they pee a lot or a little, how much fluid they take in and whether they manifest any urination-related disorders.

In addition, the parent should ensure that the child has a correct lifestyle and follows some simple rules:

go to the bathroom regularly and always pee before going to bed;
limit the intake of liquids and milk before bedtime;
do not abuse caffeinated drinks, tea and chocolate during the day;
treat constipation, if present;
practice holding your urine for a few seconds during the day.

This is a behavioural therapy, which should be followed for 1-3 months before proceeding with actual treatment if no progress is made.

What to do and what not to do

In adults as in children, it is first necessary to investigate whether there is any pathology underlying the disorder.

If the person is healthy, adopting correct behaviour becomes essential:

avoid playing sports until late at night;
do not go to bed when you are at your most tired;
eat dinner at least three hours before sleeping;
do not overdo the quantities of food;
consume foods with low sodium, no diuretic properties and a medium glycaemic index;
avoid liquid and excessively salty foods;
do not overdo fruit and vegetables;
do not drink more than one glass of water between dinner and sleep.

Medications

There are several drugs that can be used against enuresis:

desmopressin, usually in the form of a nasal spray, compensates for vasopressin hormone deficiency but can cause headaches;
imipramine, reserved for adults, relaxes the bladder and increases its capacity, but its use is burdened by several side effects;
oxybutynin relaxes the bladder muscles but is more useful when urine loss occurs during the day.

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