Bedwetting Causes

While bedwetting can be a symptom of an underlying disease, a large majority of children who wet the bed have no underlying disease that explains their bedwetting. In fact, a true organic cause is identified in only about 1% of children who wet the bed. That does not mean that the child who wets the bed can control it or is doing it on purpose. Children who wet the bed are not lazy, willful, or disobedient.

There are two types of bedwetting: primary and secondary. Primary bedwetting refers to bedwetting that has been ongoing since early childhood without a break. A child with primary bedwetting has never been dry at night for any significant length of time. Secondary bedwetting is bedwetting that starts again after the child has been dry at night for a significant period of time (at least six months).

In general, primary bedwetting probably indicates immaturity of the nervous system. A bedwetting child does not recognize the sensation of the full bladder during sleep and thus does not awaken during sleep to urinate into the toilet.

The cause is likely due to one or a combination of the following:

• The child cannot yet hold urine for the entire night.
  
  
• The child does not waken when his or her bladder is full.
  
  
• The child produces a large amount of urine during the evening and night hours.
  
  
• The child has poor daytime toilet habits. Many children habitually ignore the urge to urinate and put off urinating as long as they possibly can. Parents are familiar with the leg crossing, face straining, squirming, squatting, and groin holding that children use to hold back urine.

Secondary bedwetting can be a sign of an underlying medical or emotional problem. The child with secondary bedwetting is much more likely to have other symptoms, such as daytime wetting. Common causes of secondary bedwetting include the following:

• Urinary tract infection: The resulting bladder irritation can cause pain or irritation with urination (dysuria), a stronger urge to urinate (urgency), and frequent urination (frequency). Urinary tract infection in children often indicates another problem, such as an anatomical abnormality.
  
  
• Diabetes: People with diabetes have a high level of sugar (glucose) in the their blood. The body increases urine output to try to get rid of the sugar. Having to urinate frequently is a common symptom of diabetes.
  
  
• Structural or anatomical abnormality: An abnormality in the organs, muscles, or nerves involved in urination can cause incontinence or other urinary problems that could show up as bedwetting.
  
  
• Neurological problems: Abnormalities in the nervous system, or injury or disease of the nervous system, can upset the delicate neurological balance that controls urination.
  
  
• Emotional problems: A stressful home life, as in a home where the parents are in conflict, sometimes causes children to wet the bed. Major changes, such as starting school, a new baby, or moving to a new home, are other stresses that can also cause bedwetting. Children who are being physically or sexually abused sometimes begin bedwetting.

Bedwetting tends to run in families. Many children who wet the bed have a parent who did too. Most of these children stop bedwetting on their own at about the same age the parent did.