NCIthesaurus multiple sclerosis relapsing-remitting multiple sclerosis NCI:C165675 UMLS_CUI:C0751967 EFO:0003929 disease_ontology MESH:D020529 DOID:2378 ICD10CM:G35.A RRMS Relapsing-remitting MS SNOMEDCT_US_2025_09_01:426373005 A multiple sclerosis that is characterized by relapse (attacks of symptom flare-ups) followed by remission (periods of recovery). Symptoms may vary from mild to severe, and relapses and remissions may last for days or months. More than 80 percent of people who have MS begin with relapsing-remitting cycles.