Disease Steps is an ordinal classification from 0 to 6, plus an Unclassifiable (U) category, based on ambulation over approximately 25 ft (8 m) and the course of multiple sclerosis.

Step	Description
0 - Normal	Functionally normal with no limitation in activity or lifestyle, only minor abnormalities on examination. Relapsing-remitting course with return to baseline and no ongoing symptomatic MS therapy.
1 - Mild disability	Mild but definite MS findings (for example sensory change, mild bladder impairment, slight incoordination, weakness or fatigue) without visible gait abnormality. Often relapsing-remitting, may not fully return to baseline after attacks, and may use symptomatic therapy.
2 - Moderate disability	Visibly abnormal gait but able to walk 25 ft without an ambulation aid. Relapsing-remitting or progressive disease course.
3 - Early cane	Intermittent use of a cane or other unilateral support, mainly for longer distances, able to walk at least 25 ft without it. Relapsing-remitting or progressive course.
4 - Late cane	Dependent on a cane or other unilateral support and unable to walk 25 ft without support (may rely on furniture or walls indoors). May use a scooter for longer distances.
5 - Bilateral support	Requires bilateral support (such as two canes, two crutches or a walker) to walk 25 ft, may use a scooter for greater distances.
6 - Confined to wheelchair	Essentially confined to a wheelchair or scooter, may manage only a few steps and cannot walk 25 ft even with bilateral support. May have progression in hand function or transfers.
U - Unclassifiable	Substantial disability not captured above, such as severe visual or cognitive impairment, overwhelming fatigue, or major bowel or bladder dysfunction in a patient with otherwise limited physical disability.

Disease Steps for Multiple Sclerosis