It is well known that children with bedwetting are unable to wake up when they pee at night. It has been believed for many years that the sleep of bedwetters is too deep but recent research has indicated that bedwetters have poor sleep quality with many incomplete arousals (awakenings). They also seem to have many ‘periodic limb movements’ during sleep, a sign that may be related to the arousal attempts.

Bedwetting is clearly an inherited disease and in approximately 70% of cases there is at least one other family member who has or had the same problem as a child. For example, if a mother was a bedwetter as a child, there is a 7 times increased risk that her children will also suffer from enuresis. A specific gene that causes enuresis has not been identified yet but current research is focusing on this assignment.

No, enuresis is not caused directly by psychological disturbances but having enuresis may cause psychological problems, especially affecting self-esteem. These changes normalize after successful treatment of enuresis. Only late-onset (= secondary) enuresis is associated with an increased risk of behavioural problems such as ADHD. Any psychological or behavioural problem should be managed independently of the enuresis symptoms.

Increased night-time urine production (=”nocturnal polyuria) and reduced night-time bladder capacity are the two most common causes of bedwetting. It is important to know that these two causes may occur at the same time in a child. It is possible to recognize which of these two factors play a role in your child by simple home recording tools. By identifying the largest voided volume on a home diary (=”frequency-volume-chart”) it is possible to ascertain whether a child is suffering from ‘reduced bladder capacity’ (by comparing with published normal values). By home recording of nocturnal urine volume it is possible to evaluate whether the child has nocturnal polyuria. With this method, diapers are weighed at bedtime and again the following morning. The difference in diaper weight plus the volume of any urine produced during the night plus the volume of the first urine produced in the morning constitutes the total nighttime urine volume. Also, there are internationally accepted normal reference values for nocturnal polyuria.

Although most children with bedwetting since infancy have no underlying disease in either the nerve system that controls bladder function or in the anatomy of the urinary tract, this should be ruled out by a visit to your doctor. Also, the doctor will determine whether bedwetting is the only problem or if there are other issues that need to be addressed. This could be wetting during day-time, signs of ‘overactive bladder’ (frequent and strong sensation to void), faecal incontinence and constipation, and recurrent urinary tract infections. If these conditions are present they should be treated before any treatment for bedwetting is initiated.

It is not fully understood how the alarm teaches a child to control the bladder during sleep. Bladder filling and emptying is controlled by several centres located in the brain. It is believed that the noise of an alarm in some way can influence these centres and modify their function in a positive way. Most children using the alarm will start to wake up and pee before the alarm goes off and after a few weeks most children will then sleep through the night and postpone any bladder emptying until the morning. It is known that alarm treatment does not influence night-time urine production but it increases the capacity of the bladder during night.

It is essential for the alarm treatment to be a success that your son wakes up when the alarm sounds and goes immediately to the bathroom and completes the bladder emptying. If he does not wake up by himself when the alarm goes off one of you parents should rush to the bed and wake him up – every night!!

Your son is old enough to use the alarm. However, if the alarm is triggered more than once per night it does not work as efficiently and becomes a real hassle for everybody. This could be a sign that your son has both high urine production and a reduced bladder capacity at night. You should consult with your doctor who may consider prescribing combination treatment with desmopressin and alarm. The aim is one alarm per night.

Bedwetting might be caused both by a large urine volume at night and a small bladder capacity. Desmopressin generally works well in a child who only suffers from large urine volume (“nocturnal polyuria”). If desmopressin fails to work there are several possible causes: 1) your child forgets to take the tablet, 2) the bladder is also affected with a reduced capacity at night, - so even though desmopressin leads to a small urine volume it is still too much for the bladder to hold, in this case combination treatment with desmopressin and alarm could be tried 3) if your child either drinks or eats a lot just before bedtime desmopressin doesn’t work very well. Talk to your Paediatrician about these possible explanations and decide together on the next step.