August 2020 | Reviewed by: Ann Morse, MD and Virginia Skiba, MD
What is bedwetting?
Bedwetting is also called sleep enuresis. It is a parasomnia. A parasomnia involves undesired events that come along with sleep. Bedwetting occurs when a person urinates by accident in his or her sleep.
It results from a failure to wake up from sleep when the bladder is full. It may also result from a failure to prevent a bladder contraction. These are skills that you acquire as you grow and develop.
There is a wide range in the age at which these skills are gained. Urinating is a reflex for infants when they are asleep and awake. This occurs up to about 18 months of age.
From 18 months to about three years of age, a child begins learning to delay urination when the bladder is full. First the child learns to do this while awake.
At a later age, he learns to do this while asleep. The developmental maturity of the child will help determine the age at which this skill is gained.
Most children should be able to control their bladders during sleep by the time they are about five years of age. Thus, bedwetting is not considered a sleep disorder unless it occurs at least twice a week in a person at least five years of age.
Bedwetting can be primary or secondary. A child with primary bedwetting has never regularly stayed dry during sleep for six straight months.
A child or adult with secondary bedwetting developed the ability to stay dry at night and has done so for at least 6 straight months. Then he or she began bedwetting again at least twice a week for at least three months.
Vasopressin is a hormone that is produced in the pituitary gland and reduces the amount of urine that is produced by the kidneys. This hormone normally increases during sleep reducing the need to use the bathroom.
However, a small number of children with primary bedwetting lack this normal increase of vasopressin during sleep. As a result, they have more urine than their bladders can hold. If they do not wake up, then they will wet their beds.
A child’s self-esteem can be hurt when he or she wets the bed. This is the main risk involved with primary bedwetting. How well the child’s family deals with the symptom is very important. Their reaction will determine to a great extent how severe the problem becomes.