Why does multiple sclerosis cause urinary problems?

Multiple sclerosis (MS) can interfere with the communication between the brain, spinal cord and bladder, resulting in either difficulty storing urine, difficulty emptying the bladder, or a combination of both. These problems are sometimes described as neurogenic bladder dysfunction.

The bladder may become overactive, causing it to contract before it is full, or the muscles involved in emptying the bladder may not work together effectively. Urinary symptoms can change over time as MS progresses, so assessment should be tailored to the individual.

What urinary symptoms can occur with multiple sclerosis?

MS-related bladder dysfunction can cause symptoms affecting both urine storage and bladder emptying, including:

Urgency: a sudden, difficult-to-delay need to urinate.
Frequency: needing to pass urine more often than usual.
Nocturia: waking during the night to urinate.
Urinary incontinence: involuntary leakage of urine.
Difficulty starting urination: needing to wait or strain before urine flows.
A weak urine stream: urine may flow more slowly or with reduced force.
Incomplete emptying: feeling that urine remains in the bladder after urinating.
Urinary retention: being unable to empty the bladder adequately.

Urinary tract infections (UTIs) can occur alongside bladder dysfunction and may sometimes make existing MS symptoms appear worse. This means new or worsening urinary symptoms should not automatically be attributed to MS without considering infection or other causes.

How are urinary problems diagnosed in people with multiple sclerosis?

Diagnosis involves assessing the symptoms, bladder function and possible underlying causes rather than assuming that every urinary problem is caused by MS. A detailed history can establish patterns of urgency, frequency, leakage, difficulty emptying and recurrent infections.

Initial assessment may include:

Urine testing: to check for infection or other urinary abnormalities.
Bladder diary: recording fluid intake, frequency, urine volumes, urgency and leakage.
Post-void residual measurement: checking how much urine remains in the bladder after urination.
Ultrasound or other imaging: used when assessment of the urinary tract is required.
Urodynamic testing: specialised testing of bladder storage and emptying, used selectively rather than routinely in people with MS who have a low risk of kidney complications.

How are urinary problems associated with multiple sclerosis treated?

Treatment depends on whether the main problem is bladder overactivity, difficulty emptying, incontinence or a combination of symptoms.

Options may include:

Bladder training and behavioural measures: techniques to improve bladder control and establish more manageable toileting patterns.
Medication: antimuscarinic medicines may be used for overactive bladder symptoms, while beta-3-adrenoceptor agonists may be considered when appropriate.
Pelvic floor muscle training: may help selected people with urinary incontinence when voluntary pelvic floor contraction is possible.
Botulinum toxin type A: injections into the bladder wall may be considered when overactive bladder symptoms have not responded adequately to medication or medicines are poorly tolerated.
Intermittent catheterisation: may be recommended when the bladder does not empty adequately, helping to remove retained urine.

Treatment may need to be reviewed regularly because bladder function can change with MS. Ongoing assessment is particularly important where there is significant urinary retention or an increased risk of complications affecting the upper urinary tract.

What can you do to manage urinary symptoms with multiple sclerosis?

Keeping track of urinary symptoms can help identify patterns and provide useful information during medical appointments.

Practical measures include:

Keeping a bladder diary recording drinks, urination, urgency and leakage.
Maintaining adequate fluid intake rather than deliberately becoming dehydrated.
Considering reducing bladder irritants such as caffeine and fizzy drinks if they worsen symptoms.
Discussing pelvic floor exercises with a healthcare professional where appropriate.

To discuss urinary issues associated with multiple sclerosis and explore suitable treatment options, visit Mr Ali Omar’s Top Doctors profile to arrange an appointment.

References

NICE. Urinary incontinence in neurological disease: assessment and management.
European Association of Urology. EAU Guidelines on Neuro-urology.
Al Dandan HA, Coote S, McClurg D. Prevalence of Lower Urinary Tract Symptoms in People with Multiple Sclerosis: A Systematic Review and Meta-analysis. International Journal of MS Care. 2020.
Stoffel JT. Chronic Urinary Retention in Multiple Sclerosis Patients: Physiology, Systematic Review of Urodynamic Data, and Recommendations for Care. Urologic Clinics of North America. 2017.

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