Current rating scales for multiple sclerosis are unsatisfactory because they score each patient's condition without indicating the clinical context in which that score has been obtained. The Cambridge Multiple Sclerosis Basic Score (CAMBS) offers a solution to this problem by recording current status in the context of the clinical course. CAMBS distinguishes disability from handicap and indicates the independent contribution of relapse and progression to current clinical activity. Single scores of between 1 and 5 are assigned to each of these indices, giving a simple four component analysis for each clinical encounter, e.g. disability 3; relapse 1; progression 2; handicap 1.