Bedwetting can happen for a number of reasons. Understanding what the possible causes might be will help to reassure both parents and children that it’s a common issue and, most importantly, that it’s out of a child’s control. Here’s why it happens:
It might come as a surprise but there is a strong hereditary factor to bedwetting. If one parent wet the bed as a child, there is around a 40% chance that their child will too. If both parents wet the bed, the odds can rise to around 70%.
During the night the bladder should send signals to the brain that it’s full which prompts us to “hold-on” and wakes us up to use the toilet. For some children this connection has not yet been made and the brain doesn't respond to the signal of a full bladder. This often sorts itself out naturally – but some children might need treatment, such as the enuresis alarm or buzzer, to help this process.
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. Help your child increase their bladder capacity by encouraging them to drink plenty of fluid 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 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 so we don't have to wake up to urinate. Some children are simply at a stage where they produce too little of this hormone at night - and so wet the bed.
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 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.
No-one’s to blame
Any one of these reasons could explain why your child wets the bed, and it’s important to remember that it's nobody's fault. Bedwetting is something that is out of your child's control but with support, encouragement, patience and, if necessary, some form of treatment, dry nights will not be far away.