Bladder basics and causes

The bladder is part of the body’s urinary system. Every time you eat or drink your body absorbs liquids. It’s the job of your kidneys to filter waste products from these fluids and make urine. Urine then trickles down the ureters into the bladder, a balloon shaped muscle sack that expands and fills up. The brain gets the first signal from the bladder when it is about half full, letting it know that it’s almost time for emptying. When the bladder is full, your brain then lets you know it’s time to urinate. When you sit on the toilet, your brain then let’s the sphincter muscles around the urethra know that it’s time to open and for the bladder muscles to contract and empty. When we sleep, our brain produces a hormone which helps to slows down the production of urine in the kidneys. This helps to reduce our need to go to the toilet during the night.

For children to stay dry at night the body needs to be able to do three things;

• Control the amount of urine produced
• Store the urine in the bladder
• Wake up during the night to go to the toilet if the bladder is full

Many children sleep really deeply and don’t pick up on the signals that their bladder needs to empty, their bladder muscles might be overactive or, the brain doesn't produce enough of the hormone to slow down the production of urine by the kidneys. Any one of these issues can result in bladder weaknesses – both day-wetting and bed-wetting. However, as children grown up and their bodies develop, these issues usually resolve themselves.

Generally speaking, there’s a 40% likelihood of your child wetting the bed if you or your partner did. The chance rises to 70% if both parents wet the bed. Bed-wetting can continue through several generations but remember, it’s no one’s fault, it’s just your body developing.

Constipation is often an unrecognized cause of day-wetting and bed-wetting. If your child is constipated, this can push against their bladder, reducing how much urine it can hold. If both constipation and bed-wetting is a problem, doctors will often treat the constipation first. This can significantly improve, if not cure, the wetting issue. To ensure a healthy bowel and bladder, make sure your child enjoys healthy, and regular, eating and drinking habits. Try to drink more at breakfast and throughout the day, and avoiding drinking too much before bedtime. A regular toilet routine can also help.

Although it’s often thought to be a cause of bladder weakness in children, there’s little scientific evidence to support this. Low self-esteem can however be the result of a wetting problem. Depending on circumstances, this could be around the age your child starts school and becomes more social. Health care professionals emphasize the importance of reassuring your child that incontinence is something they will most likely grow out of and that there are treatment options available. Sending them positive signals can help to improve their self-esteem. Regardless of why, if your child has anxiety or low self-esteem, it’s always important to find out the cause and handle it with sensitivity.

Your child might be affected by an ‘overactive bladder’ this is where the bladder doesn’t stay relaxed and wants to empty before it’s full. This means that your child might need to go to the toilet more frequently, and feel an urgent need to go when they do. This can also be caused by a urinary tract infection, a small bladder capacity or constipation.

This is where the bladder cannot hold as much as normal. In some children a reduced capacity bladder only affects their ability to store urine overnight, while they have a normally functioning bladder during the day. It’s hard to measure how much urine your child is passing and knowing if this is the reason behind their incontinence, so it’s best to make an appointment with your doctor or health care professional. They might ask you record your child’s urination patterns in a bladder diary to help them find out what the underlying cause is. See more on visiting your doctor.

Sometimes your child might avoid going to the toilet for prolonged periods of time on purpose. It could be that they don’t want to use the toilets at school since they find them too smelly or, they don´t want to stop an activity that they’re enjoying. Children have different strategies to cope with this; they might stand with their legs crossed, or sit on the heel of the foot to keep the urine from coming out. Toilet avoidance means that they’re not emptying their bladder often enough and that they’re ignoring signals from the brain that the bladder is full. This causes urgency feelings, and increases the chances that they may not make it to the toilet in time. You can help to solve this by establishing a regular toileting routine. It might be easier to establish a one around certain events rather than times e.g. before eating or before leaving the house. Whatever is most memorable and convenient for your child. It’s also important to make sure that when they are sitting on the toilet that they have the correct posture. If they’re sitting in a position that tenses the pelvic floor muscles, e.g. sitting on the edge of the toilet with their legs together, they’ll find it difficult to empty their bladder. So encourage them to relax and take their time.

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, or their ability to get to the toilet is. Occasionally a repeated urinary tract infection or even a minor deformity in the urinary tract could also be the cause. If you’re a parent or carer who has a child with a serious injury or disability, you can find more information on our looking after loved ones. If your child is able to get to the toilet by themselves, just make sure you remove any obstacles in getting to the toilet, and ensure they’re wearing easy to remove clothing.

While we’ve covered many of the common causes of children’s urinary incontinence, there are other issues that can contribute. If you have more questions or concerns, talk with your doctor or healthcare professional.