Understanding multiple sclerosis

Multiple sclerosis (MS) is a disease of the central nervous system (CNS), which includes the brain, spinal cord and optic nerves. It is usually thought of as a single disease, but its course and symptoms vary from person to person.

Who gets MS?

Multiple sclerosis is a leading cause of non-traumatic disability for young people.¹,²
MS is twice as likely in women than men2
MS is commonly diagnosed between the ages of 20 and 403

Approximately 2.3 million or 1 in 3,000²

people in the world have MS

  • Approximately 1 in 710 people in North America have MS2

  • Approximately 1 in 925 people in Europe have MS2

  • MS prevalence is highest in countries furthest from the equator4

  • Approximately 1 in 1050 people in Australia have MS2

People with MS can experience many types of symptoms.5


Up to 90% of people with MS experience fatigue6


Within 15 years of onset, more than 50% of people with MS have difficulty walking5,7,8


Vision difficulties are common, and a first symptom in 15-20% of people with MS9


At least 80% of people with MS experience bladder issues10


Depression is approximately 2x more likely in people with MS11


Sleep problems are twice as likely in people with MS12

Symptoms can affect nearly every part of the body and the mind

MS is categorised into courses based on how the disease generally behaves and whether or not there is disease activity and a steady increase in disability over time.

For explanation of disease courses, please visit the National Multiple Sclerosis Society 13


Relapsing-remitting MS


Secondary progressive MS


Primary progressive MS

Disease activity can be measured

No matter what course of MS a person has, relapsing or progressive forms of MS may be active or inactive at different points in time.14 Disease activity may be outwardly apparent with new or worsening signs or symptoms. There can also be underlying disease activity that is detected with special equipment like magnetic resonance imaging (MRI).

A relapse, or exacerbation of MS (also known as an attack or flare-up), causes new symptoms or the worsening of old symptoms.¹⁵ The attack must last at least 24 hours and be separated from the previous attack by at least one month. Most relapses last from a few days to several weeks or even months, and can be followed by an incomplete or full recovery.
Disability progression
How fast or slow disability worsens may vary, but progression is a sustained increase in disability over time.
MRI activity
Lesions are inflamed or damaged areas of the CNS that can be seen with MRI. Lesions may appear or grow larger without immediately noticeable consequences, but can be a sign of irreversible damage and may lead to disability progression.¹⁶

More is being done

There is no cure for MS, but research continues to better understand and treat the disease.5

What causes MS?
What new ways can disease activity be monitored?
How can we better study new medicines for MS?
How can we predict which patients will benefit from a certain treatment?

MS has different disease courses


  1. Murray TJ. (2006). Diagnosis and treatment of multiple sclerosis. BMJ, 322 (7540):525-527.

  2. Multiple Sclerosis International Federation. (2013). Atlas of MS 2013. Available at: http://www.msif.org/about-us/advocacy/atlas/.

  3. MS International Federation. What is MS? Available at http://www.msif.org/about-ms/what-is-ms/.

  4. Simpson S, et al. (2011) Latitude is significantly associated with the prevalence of multiple sclerosis: a meta-analysis. J Neurol Neurosurg Psychiatry, 82(10):1132-1141.

  5. National Institutes of Health-National Institute of Neurological Disorders and Stroke. (2015). Multiple Sclerosis: Hope Through Research. Available at: https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Hope-Through-Research/Multiple-Sclerosis-Hope-Through-Research.

  6. Hemmett L, et al. (2004) What drives quality of life in multiple sclerosis? QJM, 97(10):671–6.

  7. Souza A, et al. (2010) Multiple sclerosis and mobility-related assistive technology: systematic review of the literature. J Rehabil Res Dev, 47:213–223.

  8. National Multiple Sclerosis Society. (2010). Gait or Walking Problems. Available at: http://www.nationalmssociety.org/NationalMSSociety/media/MSNationalFiles/Brochures/Brochure-Gait-or-Walking-Problems.pdf.

  9. United States Department of Veterans Affairs. Visual Dysfunction in Multiple Sclerosis. Available at: http://www.va.gov/MS/Veterans/symptom_management/Visual_Dysfunction_in_Multiple_Sclerosis.asp.

  10. National Multiple Sclerosis Society. Bladder Problems. Available at: http://www.nationalmssociety.org/Symptoms-Diagnosis/MS-Symptoms/Bladder-Dysfunction/

  11. Siegert RJ, Abernethy DA. (2005). Depression in multiple sclerosis: a review. J Neurol Neurosurg Psychiatry, 76:469–475.

  12. Lobentanz IS, et al. (2004). Factors influencing quality of life in multiple sclerosis patients: Disability, depressive mood, fatigue and sleep quality. Acta Neurologica Scandinavica, 110:6–13.

  13. National Multiple Sclerosis Society. Types of MS. Available at http://www.nationalmssociety.org/What-is-MS/Types-of-MS.

  14. Lublin F.D. et al. (2014). Defining the clinical course of multiple sclerosis. Neurology, 83(3),278-86.

  15. National Multiple Sclerosis Society. Managing Relapses. Available at: http://www.nationalmssociety.org/Treating-MS/Managing-Relapses.

  16. Erbayat A, et al. (2013). Reliability of classifying multiple sclerosis disease activity using magnetic resonance imaging in a multiple sclerosis clinic. JAMA Neurol, 70(3):338-44.


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