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Bedwetting Causes & Treatments

Understanding The Medical Causes Of Bedwetting

By Howard J. Bennett, MD

In most cases, bedwetting occurs because of a delay in the development of nighttime bladder control. However, parents often worry that a hidden medical problem could be causing their child’s wetting. The purpose of this article is to examine those causes more closely.

However, it’s also important to understand that 1 in 6 children between the ages of 4 and 12 experience bedwetting, often times without any medical complications. If a parent has questions or concerns about their child’s experiences, the best person to ask is their pediatrician.


The most common medical problem that causes bedwetting is constipation. Although it’s not serious, constipation can be tricky to diagnose and manage. Once kids are toilet trained, parents are less aware of their bowel habits. A child could be having two or three hard or pebbly stools per week, and his parents may not know about it. Some constipated children have recurring stomachaches, especially after they eat. Others have no symptoms other than being wet at night. The reason constipation can cause bedwetting is because the rectum is located behind the bladder. If the rectum full, it can push on the bladder. This can lead to bladder spasms, which can result in frequent urination, daytime wetting and/or bedwetting.

Urinary Tract Infection

The symptoms of a urinary tract infection (UTI) include frequent urination, an urgent need to go, wetting accidents during the day (mostly in younger children), and painful urination. Although children with a UTI may wet the bed, this is unlikely to be the only symptom they have. In practical terms, this means if your child has always wet the bed and has no daytime urinary symptoms, the odds of it being caused by a UTI are low.


Children with diabetes have high levels of glucose in their blood. This causes them to produce more urine, which leads to increased urination during the day. At night, they either get up frequently to go or they may start wetting the bed. (Some kids urinate frequently because they drink a lot. With diabetic children, the opposite occurs—they drink a lot to prevent dehydration because of all the urine they produce.)

Other signs of diabetes in children include hunger, weight loss and fatigue. In Type I diabetes, the kind most often seen in preadolescents, a child can develop urinary symptoms over a period of just a few weeks. Diabetes should be considered in any child who develops the sudden onset of frequent daytime urination with or without bedwetting.

Sleep Apnea

Lots of kids snore at night. In most cases, the snoring is not dramatic. That means their breathing is noisy, but comfortable. Apnea is the medical word for a cessation in breathing. The type of apnea that can cause bedwetting is called obstructive sleep apnea. This means something is blocking the child’s airway at night, which then causes snoring. If a child is deprived of oxygen during an episode of apnea, it can result in uncontrolled bladder contractions and a wet bed.

Bedwetting in children with obstructive sleep apnea usually comes on slowly and may not occur every night. If you suspect that your child is having apnea, monitor his sleep at different points during the night. Make an audio or audio/video recording, and show it to his doctor.

Sickle Cell Disease

The brain produces a hormone at night that reduces how much urine the kidneys make. Children with sickle cell disease often develop kidney problems that prevent them from reabsorbing water normally. This leads to increased urine production at night, which in turn can cause bedwetting. Kids with this problem usually start wetting the bed after being previously dry. A urine test can determine if this is what’s causing the child’s bedwetting.

Neurologic Problems

The lower part of the spinal cord contains nerves that play a role with bladder and bowel function. If a child develops a problem in this area, it can cause bedwetting. Although rare, doctors become concerned about a neurologic problem if the following symptoms are noted:

  • It occurs in a previously dry child.
  • The child has urinary symptoms during the day.
  • The child has problems with his gait.
  • The physical exam indicates a problem related to the spinal cord.


Except for constipation, medical causes of bedwetting are uncommon. If you are concerned that a medical problem is underlying your child’s wetting or he starts to wet the bed after previously being dry, you should seek medical attention.



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