Relapsing-remitting MSRelapsing-remitting MS (RRMS) is the most common form of Multiple Sclerosis (approximately 40% of all MS cases). People with relapsing-remitting MS have unpredictable relapses (attacks) or symptoms, but generally return to normal (the state of 'remission') between attacks. During this time, the person will either fully or partially recover from the symptoms experienced during the relapse. If the health of some people with relapsing-remitting MS does deteriorate after each relapse, but their condition is stable between relapses, this is called ‘worsening relapsing-remitting MS’. In people with RRMS, the course of the disease is progressive; after 10–15 years, approximately 75% of RRMS sufferers will progress to Secondary Progressive MS (SPMS)1.
References
1. Weinshenker et al., 1989, Weinshenker BG, Bass B, Ricce GPA et al. The natural history of Multiple Sclerosis: a geographically based study. 1. Clinical course and disability. Brain 1989; 112: 133―46. | 
