No one knows for sure what causes bed-wetting, but various factors may play a role.

  • A small bladder. Your child's bladder may not be developed enough to hold urine produced during the night.
  • Inability to recognize a full bladder. If the nerves that control the bladder are slow to mature, a full bladder may not wake your child — especially if your child is a deep sleeper.
  • A hormone imbalance. During childhood, some kids don't produce enough anti-diuretic hormone (ADH) to slow nighttime urine production.
  • Stress. Stressful events — such as becoming a big brother or sister, starting a new school, or sleeping away from home — may trigger bed-wetting.
  • Urinary tract infection. A urinary tract infection can make it difficult for your child to control urination. Signs and symptoms may include bed-wetting, daytime accidents, frequent urination, bloody urine and pain during urination.
  • Sleep apnea. Sometimes bed-wetting is a sign of obstructive sleep apnea, a condition in which the child's breathing is interrupted during sleep — often because of inflamed or enlarged tonsils or adenoids. Other signs and symptoms may include snoring, frequent ear and sinus infections, sore throat, and daytime drowsiness.
  • Diabetes. For a child who's usually dry at night, bed-wetting may be the first sign of diabetes. Other signs and symptoms may include passing large amounts of urine at once, increased thirst, fatigue and weight loss in spite of a good appetite.
  • Chronic constipation. A lack of regular bowel movements may make it so your child's bladder can't hold much urine, which can cause bed-wetting at night.
  • A structural problem in the urinary tract or nervous system. Rarely, bed-wetting is related to a defect in the child's neurological system or urinary system.
Oct. 12, 2011

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