What is bedwetting?
Bedwetting is a lack of night-time bladder control in a child who is otherwise completely toilet trained.
Most children under the age of seven wet their beds occasionally, but bedwetting that occurs regularly over a long period is less common and more likely to be a problem.
About 1:4 children aged 4-5 years regularly wet the bed. The problem is slightly more common in boys than in girls.
What causes bedwetting?
The nerve centres that allow a child to recognize when the bladder is full and hold back urine until reaching the bathroom are not fully developed until around the age of two. In some children, slowed development of these abilities is the cause of bed wetting; they just need time to develop control.
Small bladder capacity can also contribute to the problem, as can other factors such as an abnormality of the urinary tract that is present from birth; the presence of a urinary tract infection; a defect involving the nervous system, such as damage to the spinal cord, or spina bifida (a congenital malformation of the spine).
Bedwetting can also be caused by uncontrolled diabetes mellitus (a deficiency of the hormone insulin, leading to large amounts of urine being passed, among other symptoms) or diabetes insipidus (deficiency of a substance called anti-diuretic hormone, which is produced at the base of the brain, and which slows urine output).
However, in many of these conditions the child is likely to be incontinent during the day as well as wetting the bed at night.
The tendency to wet the bed runs in families; about 50% of bedwetting children have a close relative who has had the same problem.
As children get older they generally outgrow bedwetting. In the 6-10 age group, only 10% of children wet the bed, and only 3% continue to have problems as teenagers.
Emotional disturbances can also lead to bedwetting.
A previously toilet-trained child may start wetting the bed after the arrival of a baby brother or sister, a move to a new house, or when parents are having marital difficulties, such as bitter rows or living apart.
How is bedwetting investigated and treated?
Parents usually report repeated episodes of bed wetting to the family doctor, who tries to find the cause of the problem.
If overnight bladder control is not achieved by the age of four or five years, the problem is called primary enuresis, and physical causes are usually suspected.
Children who have been dry at night but who have reverted to bedwetting are said to have secondary enuresis; in these cases, emotional factors are more likely to be involved.
In most cases, time and parental patience, support and understanding are the only treatments necessary.
Some parents report success with special alarm systems that are designed to wake the child when he or she starts to urinate. These devices have been particularly effective with children aged over seven.
Occasionally, a drug that may decrease the dream stage of sleep and reduces the sensitivity of the bladder muscle is prescribed for older children.
New evidence shows that some bedwetters can benefit from the administration of artificial antidiuretic hormone which, if given at night, may reduce urine output.
When should I see my doctor?
You should see your doctor if a child's bed-wetting continues after the age of five and occurs more than twice a month, even after you have tried the measures described here.
What will the doctor do?
The doctor may carry out urine tests to rule out urinary tract infection or diabetes. If either of these conditions is present, treating it should clear up the bed-wetting.
Investigations may be arranged to see if it is caused by abnormalities of the bladder or urethra (the passage through which urine exits the body). For example, urography (X-ray imaging of the urinary tract), or ultrasound scanning (in which images are produced by soundwaves) may be performed.
Most of the time, such tests and examinations fail to uncover a simple cause for bedwetting. Therefore, the doctor's role is generally to offer support to parents and children until time solves the problem.
What can I do to avoid bed-wetting?
- Limit your child's evening intake of fluids.
- Wake the child for a trip to the toilet at 10 or 11pm.
- Try not to rush toilet training.
- Do not expect your child to achieve bladder control at night as soon as he or she is trained in the daytime
What can I do myself?
Exasperating as bedwetting may be, parents should not punish a child for wetting the bed, or say things that will increase the child's embarrassment, or focus undue attention on the problem.
Instead, it is far better to take practical measures.
- Limit the child's fluid intake in the evening and wake the child for a trip to the bathroom before going to bed yourself.
- Try training the child to increase the length of time he or she can go without urinating during the day, a strategy that may lead to greater control at night.
- Use a plastic mattress cover under the bed sheets.
Younger children can continue to wear nappies, but you should avoid using nappy-wearing as a humiliating punishment.
Some children respond to a system of behaviour modification in which they get points or gold stars for every night they are able to stay dry.
Is bedwetting dangerous?
Bedwetting is not dangerous in itself. The main risk is the damage it can do to a child's self-image, which can be avoided if the parents handle the episodes of bedwetting with patience, understanding and sensitivity.