Bed Wetting (Enuresis)

Dr. Parang Mehta, MD.

It is normal for babies to pass urine in their sleep.  Control over this bodily function comes with growth and maturation.  About 20% of children at age 5 wet their beds, and about 15% of them achieve control every year.  When there is an unusual delay in achieving this control, the problem of bedwetting, or nocturnal enuresis, is said to exist.  Most of the children who have this problem are boys.

Bedwetting is common, and prevents the child from participating in many childhood activities

Nocturnal enuresis is differentiated into primary and secondary forms.  Primary nocturnal enuresis refers to children who have always been wetting their beds at night.  These children have never been consistently dry by night, and their bedwetting is usually a delay of maturation.

Secondary nocturnal enuresis refers to those children who had achieved control, but have again started wetting their beds.  These children are likely to have an underlying physical disease or psychological disorder.

The Underlying Problem

As children grow older, they develop the ability to realise that the urinary bladder is full, even in their sleep.  This realisation then wakes them, and they walk to the bathroom to relieve themselves.  A delay in this normal maturation leads to the problem of bed wetting at an advanced age.

It is uncertain if these children have an actual physical disorder.  Some, but not all, of these children are very deep sleepers, and are difficult to rouse.  A few have other problems -- small urinary bladder capacity, and a few may have urgency of urination-- inability to hold the urine when the bladder is full.  

Normally, urine production at night is less than daytime, under the influence of a hormone called ADH (anti diuretic hormone).  It is suspected that children who wet their beds do not have enough ADH at night.  However, this has not been proved.  Some children habitually drink a lot of water or other fluids, and produce a lot of urine.  

Before Starting Treatment

Treatment for enuresis should only be started when the child wants it. Without motivation, success is unlikely

This is not a major medical emergency, and we should not rush into treatment.  An effort should be made to find any underlying cause of the bedwetting.

Children with primary enuresis do not often benefit from a series of laboratory tests.  Only a few of them have an underlying disease (see sidebar) as the cause of their bedwetting.  An underlying cause, if found, will make treatment of the bedwetting simple, of course.  Careful examination for any signs of these diseases by a pediatrician is a good starting point.  If necessary, some laboratory tests are done.

Bladder capacity assessment can be done by having the child drink liquids, and then measure the urine output when he says he needs to go.  The normal capacity, in ounces, is the age in years plus 2.  That is, a child of 5 years should have a capacity of seven ounces (1 ounce = approximately 30 ml).  The normal adult bladder capacity is 12-16 ounces.  If the bladder capacity is normal, the treatment of bedwetting is likely to be successful.

Underlying Diseases Causing Bedwetting

When To Treat Bed Wetting

Bedwetting is more a social problem than a medical one, and there is no emergency here.  The time to start treatment is when both the child and the parents want it.  Parents tend to get worried earlier but the child is usually not bothered till the age of 7-8 years.   That's when treatment should be given -- when the child is concerned, and wants to stop wetting the bed.

Treatment of bed wetting requires commitment and effort.  Unless the child is strongly motivated, success is unlikely.  A child who is not motivated to stop wetting the bed should not be started on treatment.


Treatment of bed wetting

Last Revision: May 20, 2020