Multiple sclerosis (MS) is a relatively common disease of young adults. Patients with MS can have a wide range of symptoms and may develop significant disability. The cause of MS is unknown, but immunological mechanisms are important. In MS, the pathological features include prominent demyelination and inflammation, but there is also evidence of neurodegeneration. Bladder symptoms are common in MS. The bladder is under neural control, and bladder disturbance is usually attributed to demyelination or loss of axons from the neural pathways, particularly those in the spinal cord, that control the bladder. However, as with other symptoms in MS, the presence of bladder disturbance does not always correlate well with MRI lesions. We speculate that other possible causes of bladder dysfunction in MS might include the effects of circulating toxic factors. Urgency of micturition is prominent in MS, and better understanding of the receptors involved in bladder sensation suggests possible treatment strategies through inhibiting these receptors.