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Relapse and remission

A relapse is a flare up of new MS symptoms, or the return of old ones. Remission is the temporary or permanent disappearance of MS symptoms.

A relapse is often defined in two ways: the appearance of a new symptom(s) or the return of old symptoms for a period of 24 hours or more. This can often be referred to as an ‘attack’, a ‘flare up’ or an ‘episode’. Both the frequency and severity of relapses are variable, unpredictable and unique to the individual. Some relapses may have little impact on day-to-day routine and symptoms may improve within a few weeks. A remission is a lessening in the severity of MS symptoms or even their temporary or permanent disappearance.

MS Society. Understanding relapsing remitting MS. Available at: Accessed March 2020.

UK | July 2020 | MUL20-C021