Bed wetting or nocturnal enuresis is defined by the involuntary flow of urine that occurs after the age when bladder control is normally established
. Nocturnal enuresis falls into two categories, primary and secondary. Primary enuresis is caused by conditions that are directly related to the condition while secondary is the result of conditions that "also" include bed wetting among their effects.
Examples of primary enuresis include a genetic connection. If a parent suffered from this condition it is highly likely one or more offspring will as well. Currently there is no scientific explanation why this occurs but it almost always does.
ADH is an anti-diuretic hormone which is produced to control the flow of urine while we sleep. Actually the urine becomes "condensed" and takes up less space in the bladder at night time. If a person does not produce sufficient ADH to handle the task they are likely to have a leakage some time during the night.
If the bladder doesn't develop fully or if it is smaller than "normal" then it obviously has less capacity. Having less capacity means that it will fill during the night even if the levels of ADH are normal. An overfull bladder will result in an involuntary flow of urine.
Secondary enuresis is a condition that is caused as a side effect of other diseases and conditions.
Any condition that affects the nervous system like stroke or spinal cord injury can result in enuresis simply because the person can't "feel" the need to go. Without knowing that their bladder is full the person certainly cannot control the leakage.
Other conditions that can result in bed wetting include diabetes, urinary tract infection, enlarged prostate, prostate cancer, and urinary tract stones.
Unfortunately adults with this condition carry a stigma and they are reluctant to speak about it or seek help. A visit to yhe doctor and an honest conversation can lead to several therapies that can more effectively control the problem.