Bladder dysfunction, which occurs in at least 80 percent of people with MS, happens when MS lesions block or delay transmission of nerve signals in areas of the central nervous system (CNS) that control the bladder and urinary sphincter. (The sphincter is the muscle surrounding the opening of the bladder, that controls the storage and outflow of urine. It is this muscle that gives people voluntary control over urination.) Symptoms of bladder dysfunction can include:
Frequency and/or urgency of urination
Hesitancy in starting urination
Frequent nighttime urination (known as nocturia)
Incontinence (the inability to hold in urine)
These symptoms can be caused by a “spastic” bladder that is unable to hold the normal amount of urine, or by a bladder that does not empty properly and retains some urine in it. Retaining urine can lead to complications such as repeated infections or kidney damage.
Issues can usually be managed quite successfully through strategies for bladder management (.pdf) including dietary and fluid management, medications, and intermittent or continual catheterization (inserting a thin tube into the bladder to remove urine).
Left untreated, bladder dysfunction can cause emotional and personal hygiene problems that interfere with normal activities of living and socialization. It is important to seek appropriate medical evaluation and treatment early, so that the cause of the bladder symptoms can be determined and treated, and complications avoided.