Multiple sclerosis (MS) is a long-term condition that affects the central nervous system (CNS), which is comprised of the brain and spinal cord.
In MS, inflammation destroys the protective myelin sheath around the neurones around the nervous in the CNS and stops the nerves from working properly. This is called demyelination.
MS varies from person to person and not everyone’s MS is the same. Although MS is individual and everyone will have a different experience, broadly speaking there are three main types: relapsing-remitting MS, secondary progressive MS and primary progressive MS.
Relapsing-remitting MS is characterised by repeated attacks (relapses) and nervous system symptoms that reflect inflammation within the CNS. Symptoms vary from patient to patient but typically involve walking diculties, numbness, vision problems or disturbed balance. Symptoms of a relapse may disappear completely when the relapse is over, but some problems may remain.
Secondary progressive MS typically happens over time and is when people who have relapsing-remitting MS begin to have fewer or no relapses, but continue to experience an increase in their disability. As this follows an initial relapsing-remitting phase, this type of MS is called secondary progressive MS.
Primary progressive MS is less common than relapsing-remitting MS. People with this type of MS see their disability increase from the beginning, rarely experiencing relapses.
CNS = central nervous system; MS = multiple sclerosis.