Are you the type of person who routinely goes to the bathroom before you leave your house, even if you don’t really have a full bladder? Do you encourage your kids to pee before getting into the car? Are you emptying your bladder before meetings, a movie, or a workout?
If you answered yes to any of the above questions, you may be training your bladder to signal to your brain that it is time to urinate when it is not actually full.
A healthy bladder can hold between 300 and 500 milliliters of urine, and even more at night (for reference, a standard can of soda holds 355 ml). When the bladder is about halfway full, stretch receptors located in the smooth muscle of the bladder walls will become active and stimulate the micturition reflex. This reflex causes the detrusor muscle in the bladder to contract and the internal urethral sphincter to relax. The bladder also transmits a signal to the brain which is interpreted as an urge to urinate. In addition to the internal sphincter, we have an external sphincter that we can voluntarily control. Relaxing or contracting this sphincter determines whether urine is allowed to exit the body. Contraction of the external sphincter will calm the detrusor muscle and the urge to urinate will dissipate as a result.
When you habitually urinate “just in case,” you may be emptying your bladder when it is less than half full. Constantly doing this will train your bladder to think it is full when it is not. The stretch receptors will begin to send signals to your brain at lower and lower thresholds, thus creating the urge to urinate more and more frequently.
In my practice as a pelvic floor therapist, I see the habit of “just in case” voids all too often. Usually it starts as a behavior learned early in life or during pregnancy. If you find that you are going to the bathroom frequently, routinely urinating less than fifteen seconds in duration, or waking up multiple times a night to urinate, I would recommend that you see a pelvic floor therapist to address these issues. Just as the bladder can be trained to hold less urine, with physical therapy, the bladder can also be trained to comfortably hold more!