Respiratory
Oncology
Neurology
Therapeutic Area
Multiple Sclerosis
Multiple sclerosis (MS) is a condition that happens when the immune system attacks the brain and spinal cord.
About MS
Multiple sclerosis (MS) is a condition that happens when the immune system attacks the brain and spinal cord.
Symptoms of MS vary from person to person and depend on the location and severity of nerve fiber damage. These often include vision problems, tiredness, trouble walking, and keeping balance, and numbness or weakness in the arms and legs. Symptoms can come and go or last for a long time.
The causes of MS are not known, but a family history of the disease may increase the risk.
Key Facts
Multiple sclerosis (MS) affects function in cognitive, emotional, motor, sensory, or visual areas, and occurs as a result of a person’s immune system attacking their brain and spinal cord.
It is estimated that over 1.8 million people have MS worldwide.
People of all ages can be affected, but it is more common in young adults and in females.
MS can improve or stabilize by being treated with medicines early in the course of the disease. Treatments will be different for each person depending on the severity of the disease and symptoms.
MS can present in a variety of ways including:
- Clinically isolated syndrome (CIS): describes an episode of neurologic symptoms that are the first clinical sign of possible MS;
- Relapsing remitting (RRMS): the most common form of MS, characterized by intermittent attacks of symptoms (relapses), followed by a short or long period of no clinical attacks (remissions);
- Secondary progressive (SPMS): after living with RRMS for a long period of time, relapses decrease and symptoms continue progressively without relapses or remissions;
- Primary progressive (PPMS): starting from the initial symptoms, the disease gradually progresses and gets worse without any clear relapses or remissions.
MS is not always easy to diagnose in its early stages. Typically, people who have been diagnosed with MS will have been through several diagnostic stages, which can be an unsettling and frightening experience.
Symptoms
Symptoms of multiple sclerosis can be different from person to person. They can come and go, or get worse over time. MS can affect any part of the central nervous system.
MS symptoms can worsen with heat or during other infections, such as urinary tract or respiratory infections.
Symptoms can include:
- Vision problems
- Walking or balance difficulties
- Cognitive difficulties
- Numbness or weakness, especially in the arms and legs
- Muscle stiffness
- Depression
- Sexual or urinary function problems
- Fatigue
Causes
MS is an inflammatory demyelinating condition that results from an autoimmune attack on myelin, the fatty insulation that surrounds the nerves in the brain and spinal cord. This disrupts the electrical impulses that are sent through the nerves to the rest of the body, and results in scars (plaques or sclerosis).
It is not known what triggers the immune system to attack myelin, but genetic and environmental factors are thought to play a role. MS happens most commonly in young to middle-aged adults, more in females than males, and is more common in higher latitudes, possibly due to sun exposure and vitamin D.
Diagnosis
MS is a diagnosis of exclusion and there are no definitive diagnostic tests. Magnetic resonance imaging (MRI) can help with diagnosis by showing plaques or sclerosis on the brain and spinal cord. Other tests, such as lumbar puncture, optical coherence tomography (OCT), and visual evoked potentials, can also help support the diagnosis.
Treatment and Care
Treatments for MS will be different for each person. They depend on the stage of the disease and symptoms.
The goals of MS treatment are to reduce the frequency and severity of relapses, slow disease progression, manage symptoms, and improve quality of life.
Specific MS disease-modifying therapies (DMTs) are started as early as possible to slow disease progression and prevent relapses.
Steroids are sometimes used in the short term to treat relapses. Other medicines can be used to reduce the symptoms of MS, such as fatigue, muscle tightening, depression, and urinary or sexual problems. These medicines do not change the course of the disease but help manage the symptoms.
Rehabilitation specialists can help improve functioning, quality of life, and reduce muscle stiffness and spasms.
Many people feel fatigue with multiple sclerosis. Ways to manage fatigue include:
- Regular exercise
- Healthy sleep patterns
- Avoiding medicines that make fatigue worse
In the past twenty years treatment options for MS have improved dramatically. Many oral, intravenous and injectable options exist to treat MS. However, most of these medications are available and there is still a lack of treatment options for progressive types of MS.
References
World Health Organization. “Multiple Sclerosis.” Fact Sheets, August 7, 2023. https://www.who.int/news-room/fact-sheets/detail/multiple-sclerosis
World Health Organization. “WHO’s Decision Brings Hope to People with MS Worldwide.” MS International Federation, July 25, 2023. https://www.msif.org/news/2023/07/25/whos-decision-brings-hope-to-people-with-ms-worldwide/
MS International Federation. Atlas of MS 2020 – Epidemiology Report. London: MSIF, 2020. https://www.msif.org/resource/atlas-of-ms-2020/
Khan, Gulfaraz, and M. Jawad Hashim. “Epidemiology of Multiple Sclerosis: Global, Regional, National and Sub-National-Level Estimates and Future Projections.” Journal of Epidemiology and Global Health 15 (2025): Article 21. https://link.springer.com/article/10.1007/s44197-025-00353-6
Walton, Clare, Rachel King, Lindsay Rechtman, Wendy Kaye, Emmanuelle Leray, Ruth Ann Marrie, et al. “Rising Prevalence of Multiple Sclerosis Worldwide: Insights from the Atlas of MS, Third Edition.” Multiple Sclerosis Journal (2020). https://journals.sagepub.com/doi/pdf/10.1177/1352458520970841
Cochrane Multiple Sclerosis and Rare Diseases Group. “Treatments for Multiple Sclerosis Are Now Among the WHO Essential Medicines.” Cochrane MS Group News, February 24, 2023. https://ms.cochrane.org/news/treatments-multiple-sclerosis-are-now-among-who-essential-medicines