The causes of children’s bladder weakness

Bed wetting is the most common form of children’s incontinence with day wetting affecting just 2-4% of 5 to 7 year olds. The following are the most common causes of children's bladder weakness.

Developmental Causes

The bladder empties by opening and contracting muscles in response to signals from the brain that it is full. If this nerve/muscle coordination is slow to develop, the bladder can sometimes fill before the child’s brain knows about it. Alternatively, the muscle (valve) could just be too weak.

Children usually sleep more deeply than adults and take longer to fully wake up. This sometimes means they don’t sense the signal telling them to empty their bladder - or else can’t wake up in time. 

At night, the body produces a larger amount of anti-diuretic hormone, or ADH. This slows the production of urine, reducing the need to urinate. If, for any reason, it fails to do this, the bladder may overfill.

All of the above conditions usually resolve themselves with time. Anxiety is also often thought to be a cause of bladder weakness in children but there’s little scientific evidence to support this. However, if your child is anxious, it’s important to find out the cause and handle it sensitively.

Medical Causes

Bladder weakness in children could also be a side effect of a medical condition or disability. In cases of cerebral palsy, spina bifida, brain injury or nerve damage, the ability to receive the correct signals from the brain to empty the bladder may be physically impaired. Occasionally a repeated urinary infection or even a minor deformity in the urinary tract could also be the cause.

If you’re a carer for a child with a serious injury or disability, you’ll find more information when you go to our Looking After Loved Ones section.

The hereditary link

There appears to be a hereditary link to bladder weakness, which can continue through several generations. Broadly speaking there’s a 40% likelihood of a child wetting the bed if one parent did, rising to 70% where it was both parents.

Day wetting

Daytime wetting, when not caused by a urinary infection or anatomic reasons, could result from an overactive bladder or infrequent voiding. 

Overactive Bladder

This concerns the muscles surrounding the urethra that are used to prevent the passing of urine. What happens is that they contract involuntarily, forcing the urine out. It is often a consequence of a urinary infection and is more common in girls.

Infrequent voiding

Some children put off going to the toilet, either because they don’t like using the school facilities or because they don’t want to miss out on something and ignore their urge. This can lead to an overfilling of the bladder and accidental urination. It can also cause infections.

Functional Incontinence in children

This is where your child is physically unable to reach the toilet. It may be due to problems with movement or it could be because your child uses a wheelchair. In the latter case, it is likely to be both faecal and urinary incontinence. If your child is able to get to the toilet on their own but this takes time, make sure access to the toilet free is of obstacles and ensure they have clothing that is simple to remove. However the most important thing is to use protective underwear that keeps them dry and comfortable. This limits the risk of irritations and skin infections which are often suffered by people who are seated or lying down for long periods.

You will realise by now that there can be several causes of bladder weakness in children. Certainly, everyone’s experience is different. So if you’re unsure, we advise you to contact a healthcare professional for a personal assessment, which normally starts with finding out when your child experiences urine loss and under what conditions. It might be an idea to keep a diary recording your child’s urination pattern for a week so you can monitor what happens. You’ll then have a record to discuss with your Doctor or continence advisor should you wish to. Download a bladder diary. 

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