There are a number of reasons for bedwetting. Understanding the possible causes can help reassure both you and your child that bedwetting is a common issue and not something your child has control over.
While we’re asleep, the bladder sends signals to the brain to indicate it’s full. This is how we know to “hold on” and wake up to use the toilet. Some children haven’t formed this connection yet, resulting in the brain not responding to these signals. It’s common for children to wet the bed and they will likely become dry in their own time
Small bladder capacity
For some children a smaller than average bladder capacity (the amount the bladder can hold before getting the sensation of fullness) can result in frequent trips to the loo during the day, as well as problems at night. You can help your child increase their bladder capacity by encouraging them to drink plenty of fluids during the day (for children 4-8 years the 2010 Guidelines by NICE recommend 1,000 - 1,400mls of fluids a day, which is equivalent to about 6-8 glasses).
Lack of hormones
When we go to sleep, our pituitary gland secretes a higher level of an antidiuretic hormone (ADH) that slows down the production of urine by the kidneys. That way, we don't have to wake up to urinate. Some children are simply at a stage where they’re producing too little of this hormone at night, which can result in bedwetting.
Constipation is a recognised trigger for bedwetting episodes in some children. This is because the constipated bowel literally “leans” on the bladder and causes the bladder to empty before it is full. In this instance, it’s important to sort out the constipation first, as this will most likely also resolve the bedwetting.
In some cases, a urine infection can cause bedwetting. So if having a wee is causing your child pain, or if they are passing urine much more frequently than usual, talk to your doctor.
This can be a trigger for a few children – especially if they have been dry at night for over 6 months then start wetting again. Talking to your child about what might be worrying them can help sort out the bedwetting with time.
No one’s to blame
Any one of these reasons could explain why your child is wetting the bed, and it’s important to remember that it's nobody's fault. And while bedwetting is something that’s out of your child's control, with support, encouragement and the right management methods, dry nights will not be far away.