Researchers have discovered why jumping into a cold pool, walking barefoot on a cold floor or entering a cold air conditioned room makes you have the urge to go to the bathroom. Parents mention that their child has to go to the bathroom more urgently than normal when they spend the afternoon swimming. Now we have a physiologic reason for this.
Not a conditioned response
Many people assumed that the cold and running water were just associated with going to the bathroom, so a subconscious bladder contraction was learned. But the researchers found that even in anesthetized mice, the cold-induced bladder contraction was present. Warmth had no effect.
It was found that ion channels in the bladder cell membrane play a role. One particular channel, TRPM8, acts as a molecular thermometer and is responsible for the cold-induced urge to urinate.
Help for people with overactive bladders
Some people with overactive bladders experience a sudden involuntary loss of urine when exposed to everyday cold stimuli. Since we have been able to identify the exact molecular channel, an experimental drug to block these cold-induced urges to urinate may be useful.
Any effect for bedwetting
Parents sometimes report more bedwetting in the winter or when their child had kicked off their blankets. An interesting study from Japan also reported that children using bedwetting alarms in the summer were more successful than those using it in them in the winter. Could it be that the cold-induced bladder contractions make a difference?
More research needed
Until further research is completed, make sure your home and child’s room is warm so the cold reflex does not play a role in their bedwetting.