MS and Bladder Problems

EvergreenHealth MS Center

The bladder is a vital part of our normal anatomy. The kidneys remove waste products from your blood and expel them in your urine. The normal range for an adult urinary output is between 1/2L to 2L per day given a normal fluid intake of about 2 liters per day (1/2 a gallon). The normal bladder capacity is ¼ to ½ liter (1-2 cups), so unless deprived of fluids, a person needs to empty the bladder several times per day. 

There is a lot of neurological input into the process of storing urine in the bladder, signaling the brain of need to empty and then coordinating contraction of the bladder muscle with relaxation of the bladder outlet to achieve complete and timely emptying. The complex process of urination is prone to fail when there is damage to the brain and spinal cord in multiple sclerosis (MS). 

Bladder problems are present from disease onset in 35% of people with MS and over 80% will eventually have some urination dysfunction. Urinary problems have a major psychological impact, and are among the most socially disabling manifestations of MS. Types of bladder dysfunction include problems of storage, problems of emptying, and a combination of both. Storage problems are the most common, typically caused by an “overactive bladder,” where the bladder begins to contract prematurely with a small volume of urine. Symptoms of an overactive bladder are urgency (feeling pressure or need to empty soon/hard to hold on to it), frequency (urinating more often than normal (>7x/day), including during the middle of the night), and having incontinence (bladder accidents).  Problems of emptying (urinary retention) in MS are usually caused by inadequate signals to make the bladder outlet relax and let the urine flow. With combined dysfunction, there is simultaneous bladder overactivity and trapping of urine at the outlet. The symptoms of combined dysfunction are urgency, hesitancy, frequency and incontinence.  As if these symptoms are not enough, bladder dysfunction may lead to skin care problems, bladder infection, bladder stones and damage to the ureters and kidneys.