The pattern which multiple sclerosis follows differs for different people. The relapsing/remitting form of MS follows a course of relapses (also known as "attacks") where there is an increased level of symptoms, followed by remissions in which there are less, or no, evident symptoms. The periods of acute attack occur when the myelin sheath is inflamed, squeezing the nerve fibers so that messages do not pass clearly from the brain to other parts of the body. The frequency and severity of relapses varies. In a few cases, people with relapsing/remitting MS may go on to develop secondary progressive MS.
