What causes bedwetting?

Many children who wet the bed feel embarrassed and alone. Bedwetting is a common problem and is not the fault of your child. Bedwetting happens when there is no conscious awareness during sleep that they might need the toilet.

It could be any of the following reasons:


  • Lack of a hormone called vasopressin

This regulates the amount of urine produced by the body during the night. If there is not enough the kidneys continue to produce large amounts of urine which the bladder can’t hold.

  • Small bladder size

A small sized bladder will not have the capacity to store urine for the 10-12 hours the child is asleep.

  • Constipation

If the bowel is full it can press against the bladder, reducing its capacity and affecting its ability to store urine overnight.

  • Urinary tract infection (UTI)

This can give a feeling of always needing the toilet and can cause or exacerbate any problem.

  • Inability to wake from sleep

Inability to wake from sleep at the signal of a need to empty the bladder.

  • Inherited tendency to wet at night

We know that if one parent had a problem with bedwetting then there is approximately a 40% risk of their children also having a problem and that risk may increase if both parents had a bedwetting problem.

  • Anxiety, stress or changes in routine

    Events like starting school, the birth of a new sibling, exams and or bullying can delay a child becoming dry at night or can cause bedwetting in a child who had previously been dry.