Bedwetting is common for children, affecting more boys than girls. The condition occurs in approximately 15% of children at the age of 5 years, 7% of children at the age of 8, and declines to 1% to 2% of children by the age of 15 years. It continues to affect 0.5% of individuals into adulthood. When a child who is old enough to have bladder control urinates accidentally while sleeping, it's called nocturnal enuresis.

There are two main types of nocturnal enuresis: primary and secondary. The primary type is a condition where a child still wets the bed after age 5 or 6. It's often hereditary. The secondary type occurs when a child who had stopped bedwetting for at least six months starts again, often due to emotional stress or a medical condition.

Possible causes of primary nocturnal enuresis include the following:

• delay in maturation of bladder control or incomplete toilet training
• genetics – children with parents who also wet the bed beyond age 5 are at an increased risk for bedwetting
• constipation – this may not allow children to empty their bladder completely
• urination patterns – children who suppress their urge to urinate or postpone urinating may not develop coordination with sphincter control and bladder control
• high nighttime urine volume

Rare possible causes include the following:

• problems with antidiuretic hormone (ADH), a hormone that causes the body to retain water – normally, ADH levels increase at night to decrease the amount of urine produced; however, children with enuresis do not have increased ADH levels at night, causing greater urine production, which can lead to bedwetting
• minor nerve damage – this may decrease a child's ability to sense a full bladder

Although it is often said that emotional stress causes primary nocturnal enuresis, there is little scientific evidence to support this claim. However, bedwetting itself may lead to feelings of shame and lowered self-esteem.

Causes of secondary nocturnal enuresis include the following:

• emotional stress (e.g., birth of a sibling, significant loss, family discord)
• urinary tract infection
• diabetes mellitus (rarely)

For sleeping children who are old enough to control their bladders, the symptoms of bedwetting are obvious. Regularly finding urine-soaked sheets is a clear sign of the problem. Also, a child may wake and cry during the night when the wetting occurs, or wake up caregivers to alert them.

The most common complication of bedwetting is the impact on self-esteem and the emotional distress it causes children. Assuring children that the occurrences are accidental (and not blaming the condition on them) is key to managing the psychological effects. Many children who wet the bed may fear staying overnight at a friend's house in case they wet the bed there.

Since many children under the age of six still wet the bed, any one of the following signs should signal the need to consult a doctor:

• a child who is wetting during the day after the age of 6
• a child who starts bedwetting at night after having stopped for six months or more
• any signs of nerve damage (e.g., loss of sensation), especially in the legs
• snoring and daytime drowsiness, which may indicate sleep apnea
• urinary symptoms such as urinating frequently or having pain with urination
• excessive weight loss or thirst

Laboratory tests can be done to make sure the bedwetting isn't caused by a urinary tract infection or by other medical conditions such as diabetes. Treatment can usually be started if these medical conditions are found.

Children under the age of 5 or 6 aren't treated for bedwetting because they generally outgrow the problem.

Here are some strategies for parents to help children who are wetting the bed:

• Realize that bedwetting is fairly common up to age 5 to 6.
• Keep a matter-of-fact attitude and convey that this is nothing out of the ordinary.
• Don't blame the child; offer support and encouragement instead.
• Point out that bedwetting is common, that it can be corrected, and that there's nothing to feel guilty about.
• Don't get angry when your child wets the bed, because this can cause the child to give up trying to stop bedwetting, or can lead to emotional problems.
• Don't give lots of fluid or caffeine (like chocolate or cola beverages) to children before bedtime.
• Give most of the child's daily fluid in the morning and early afternoon (40% in the morning, 40% in the early afternoon, and 20% in the evening). Restricting all fluids in the evening may prevent children from getting enough hydration.
• Encourage your child to urinate before going to bed (up to 4 to 7 times in the evening and before bed).
• Make sure your child has easy access to the toilet, and encourage them to get up and go to the toilet if they feel the urge to urinate during the night.
• Keep a night light on in the bathroom so children can change their clothes or go to the washroom.
• Keep a calendar of wet and dry nights – this will help you to determine what works and what doesn't.

Actively treating bedwetting may be helpful if a child's relationships or school performance are being significantly affected. Treatment may involve bedwetting alarms or medications.

A bedwetting alarm is triggered when the child passes the first few drops of urine and wakes him or her up. Alarms become effective for most children after they have been used for 12 weeks. Alarms are most effective for children over 7 or 8 years of age. For alarm treatment to be successful, the child must be motivated and the parents must be willing to have their sleep interrupted. In some cases, the child may not be woken up by the alarm during the first few weeks, and parents must wake the child.

Medications are another option for bedwetting. Children 5 years of age and older may take desmopressin,* a medication that decreases the amount of urine the body makes, but this won't stop bedwetting completely. Special care should be made to avoid drinking fluids one hour before and eight hours after taking this medication. Side effects include sinus congestion, runny nose, headache, and abdominal pain.

Another option is to use a class of medications called tricyclic antidepressants. This usually involves a medication called imipramine, but other tricyclic antidepressants such as amitriptyline and desipramine may also be used. All of these medications are available for children older than 6 years. They work immediately to prevent bedwetting. Side effects such as changes to sleep patterns, headache, and appetite changes may occur. These medications should be safely stored away from children between doses.

If there are family problems (psychiatric or emotional) affecting either the child or another member of the family, these may also be root causes of bedwetting and need attention. Otherwise, the bedwetting can lead to life-long emotional and psychological distress.