What is bedwetting?
Bedwetting, also known as nocturnal enuresis, is the accidental or involuntary release of urine during sleep. Bedwetting is a common problem among children, even after they have been toilet-trained.
Most children gradually stop wetting the bed on their own as they grow older. Usually, children stop wetting the bed between 3 and 5 years of age. Bedwetting is considered a problem if the child is over age 5 and continues to wet the bed two or more times a week for at least three months in a row.
Although bedwetting is not a serious condition, it can cause stress for the child and family. Children who wet the bed may feel ashamed or embarrassed. They might avoid taking part in activities, such as sleepovers or camping, because they are worried that they might wet the bed while they’re away from home.
There are two main types of bedwetting — primary and secondary nocturnal enuresis:
- Primary nocturnal enuresis is a condition in which the person has never remained dry throughout the night for 6 months in a row or longer.
- Secondary nocturnal enuresis is a condition in which the child has started wetting the bed again after not wetting the bed for 6 months or more. Secondary enuresis is more likely to be caused by a medical problem or psychological condition.
Diurnal enuresis is a condition in which a child cannot hold his or her urine at any time of the day or night. This is more common among younger children.
How common is bedwetting?
About 5 million children in the United States wet their beds. It happens more often among younger children. About 2-3% of people over 18 have primary nocturnal enuresis. Bedwetting occurs more often among boys.
What causes bedwetting?
Usually, there is no medical or psychological condition that causes bedwetting. (A small percentage of children who wet the bed do have a medical condition.) Bedwetting can be caused by many things, including:
- Family history: Children with a parent or parents who were bedwetters are more likely to wet the bed.
- Constipation: Pressure from extra stool inside the rectum may interfere with the nerve signals that the bladder sends to the brain. A full rectum can also reduce the amount of urine that the bladder can hold or prevent it from emptying completely during urination.
- Hormones: A hormone called vasopressin limits the volume of urine that the body produces during the night. Vasopressin works by causing water in urine to be reabsorbed by the bloodstream, so a smaller volume of urine enters the bladder. Children who do not produce enough vasopressin might be more likely to wet the bed.
- Small functional bladder capacity: Children with small functional bladder capacity have normal-sized bladders, but they sense that their bladders are full even when the bladder can still hold more urine. They tend to urinate more often during the day and might have a sudden urge to run to the bathroom to prevent an accident. They also are more likely to wet the bed during the night.
- Failure to awaken during the night: Sometimes children are unable to wake up in time to get to the bathroom. As the bladder fills with urine, it sends a signal to the brain, which sends a signal back to the bladder to relax so it can hold more urine. A full bladder continues to send signals to the brain so that the child will awaken. Bedwetting occurs when the child has not yet learned to respond to these internal signals.
- Psychological or emotional problems: Emotional stress caused by traumatic events or disruptions in a child’s normal routine can cause bedwetting. For example, moving to a new home, enrolling in a new school, or the death of a loved one may set off bedwetting episodes that become less frequent over time.
- Sexual abuse: Children who begin wetting the bed again after they have learned to stay dry may be victims of sexual abuse. Other signs of abuse include frequent urinary tract infections, vaginal pain, itching or an unusual discharge, or a sexually transmitted disease.
- Medical conditions: Disorders that are associated with bedwetting include urinary tract infections, diabetes, sickle cell disease, and sleep apnea. Neurological problems or kidney or bladder abnormalities may also be causes. If bedwetting recurs after your child has been dry for 6 months or more, a medical condition may be causing it.