Dr Catherine
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4-7 years

My daughter sometimes wets the bed every night for a week, but then could go a few days without wetting the bed at all! She just doesn't wake up to go to the toilet.

Hi Sarah, While doctors and researchers have been able to identify some known causes, there is still an air of mystery surrounding some aspects of bedwetting. Contributing factors include a small bladder capacity, genetic predisposition to the condition, and the absence of ADH (antidiuretic hormone) - children without ADH produce four times the amount of urine as those who have the hormone and are therefore at a greater likelihood of exceeding their bladder capacity overnight. In general, we find that children stop wetting the bed when their bodies become better able at storing the urine overnight or they learn to wake-up on their own in response to a full bladder. Researchers have shown that while deep sleeping certainly plays a role in bedwetting it is not the primary cause of why it happens in the first place. Children who are particularly deep sleepers fail to wake in response to the message sent by the bladder to the brain saying it is full and requires emptying. The bladder then attempts to either store the urine or it empties while your child sleeps. The many known (and unknown!) causes of bedwetting go someway toward explaining why we experience such variable responses to the range of treatments available. The fact that she is able to go some nights without wetting is a very encouraging sign that her bladder does have the capacity to store urine overnight. Conditioning alarms are currently the safest and most effective means of treating bedwetting. Children who experience variable or less frequent wetting like your daughter tend to respond better to the conditioning alarm. There are a number of different styles available so it is best to meet with a continence advisor first to discuss your individual needs. All the best! Regards, Dr Cathrine