About Multiple Sclerosis
Multiple sclerosis (MS) is an autoimmune condition in which the body's immune system mistakenly attacks myelin, the insulating layer around nerve fibers in the central nervous system. This damage, called demyelination, creates scar tissue (sclerosis) that disrupts nerve signals. The disease follows several distinct clinical courses. Relapsing-remitting MS (RRMS) is the most common form at diagnosis, affecting about 85% of patients, with clearly defined attacks followed by partial or complete recovery. Some RRMS patients eventually transition to secondary progressive MS (SPMS), with steadily worsening disability independent of relapses. Primary progressive MS (PPMS) affects about 10-15% of patients and involves gradual decline from onset without distinct relapses. Clinically isolated syndrome (CIS) refers to a first episode of neurological symptoms that may or may not develop into MS, while radiologically isolated syndrome (RIS) describes incidental MRI findings suggestive of MS in people without symptoms.
The cause of MS is not fully understood but involves a combination of genetic susceptibility and environmental triggers. Over 230 genetic variants have been identified through genome-wide association studies, with the HLA-DRB1*15:01 allele being the strongest individual risk factor, roughly tripling the odds of developing MS. However, MS is polygenic, meaning no single gene causes the disease, and these common variants together explain only about half of the estimated heritability. There is currently no clinically useful genetic test for diagnosing or predicting MS. Polygenic risk scores are being developed in research settings but do not yet have enough predictive accuracy for clinical use. Epstein-Barr virus infection, particularly the immune response to the viral protein EBNA1, plays a critical and possibly causal role through molecular mimicry with brain proteins like GlialCAM. Research published in 2025 showed that carrying specific anti-EBV antibodies combined with certain genetic risk factors dramatically increases MS risk. Diagnosis relies on the McDonald criteria: MRI imaging showing characteristic brain and spinal cord lesions disseminated in space and time, neurological examination, and sometimes cerebrospinal fluid analysis.
Treatment options have expanded dramatically over the past two decades, with more than 20 FDA-approved disease-modifying therapies spanning multiple drug classes: injectable interferons and glatiramer acetate, oral therapies including S1P receptor modulators (fingolimod, siponimod, ozanimod, ponesimod), fumarates (dimethyl fumarate, diroximel fumarate, monomethyl fumarate), teriflunomide, and cladribine, as well as infusion therapies such as natalizumab, ocrelizumab and ublituximab (anti-CD20 antibodies; ublituximab, sold as Briumvi, was FDA approved in December 2022), and alemtuzumab (anti-CD52), and ofatumumab (Kesimpta), an anti-CD20 drug injected under the skin at home. Ocrelizumab is also available as a twice-yearly under-the-skin injection given at a clinic (Ocrevus Zunovo, approved September 13, 2024). Treatment selection depends on disease activity, subtype, risk tolerance, and patient preference, with high-efficacy therapies used early in the disease course increasingly favored over the traditional escalation approach.
Common Symptoms of Multiple Sclerosis
Recognizing the signs of Multiple Sclerosis early can lead to faster diagnosis and better outcomes. Symptoms may vary in severity from person to person. If you or a loved one are experiencing any of the following, consider speaking with a specialist.
- Numbness or tingling in limbs, often on one side
- Vision problems including optic neuritis and double vision
- Fatigue that is disproportionate to activity level
- Muscle weakness, spasticity, and difficulty walking
- Cognitive changes including memory and concentration problems
- Bladder and bowel dysfunction
- Lhermitte's sign (electric shock sensation down the spine when bending the neck)
- MS hug (band-like tightness or pressure around the torso)
- Heat sensitivity causing temporary worsening of symptoms (Uhthoff's phenomenon)
- Pain and neuropathy including trigeminal neuralgia (intense facial pain caused by nerve damage)
- Balance and coordination problems (ataxia)
- Speech difficulties and swallowing problems (dysphagia)
Who Multiple Sclerosis Affects
Typically diagnosed between ages 20 and 50, with women affected 2-3 times more often than men. More common in people of Northern European descent and those living farther from the equator. Family history increases risk but MS is not directly inherited. Having a first-degree relative with MS raises lifetime risk to about 2-4%, compared to 0.3% in the general population.
Epstein-Barr virus (EBV) infection is considered a necessary (though not sufficient) risk factor, with a landmark 2022 military cohort study (Bjornevik et al., Science) showing EBV increases MS risk roughly 32-fold. Other environmental risk factors include vitamin D deficiency, smoking, and adolescent obesity.
Find Your Next Step
FDA-Approved Treatments for Multiple Sclerosis
There are currently 23 FDA-approved medications for Multiple Sclerosis. These therapies represent the current standard of care and may be used alongside or compared against investigational treatments in active clinical trials.
Source: openFDA drug labeling data. This list may not include all treatments. Always consult your doctor.
Multiple Sclerosis Medicines in Clinical Trials
Investigational medicines Trial Friend tracks for Multiple Sclerosis, with trial results, safety findings and where each one stands.
Help Paying for Multiple Sclerosis Treatment
Charity funds and drugmaker programs for Multiple Sclerosis, checked at the source.
- From a charity · The Assistance FundMultiple Sclerosis fundWaitlist
Pays for: Copays, coinsurance, deductibles and other health-related expenses.
The foundation says: “WAITLIST — Accepting Waitlist Patients. TAF is currently accepting requests to join the enrollment waitlist for this program. Waitlists a…”
- Briumvi (Ublituximab) · BRIUMVI Patient Support (TG Therapeutics)
- Gilenya (Fingolimod) · Novartis Patient Assistance Foundation
- Copaxone (Glatiramer acetate) · COPAXONE Co-Pay Solutions
- Aubagio (Teriflunomide) · MS One to One (AUBAGIO Co-Pay Program and One Start)
- Zeposia (Ozanimod) · ZEPOSIA 360 Support
- Ocrevus (Ocrelizumab) · OCREVUS Access Solutions
- Tysabri (Natalizumab) · Biogen Support Services
- Kesimpta (Ofatumumab) · Novartis Patient Support
- Tecfidera (Dimethyl fumarate) · Biogen Support Services
- Mayzent (Siponimod) · Novartis Patient Assistance Foundation
Side Effect Explorer
Real-world side effect reports from the FDA Adverse Event Reporting System (FAERS). Includes both FDA-approved drugs and investigational therapies from active clinical trials. Click any drug to see what patients reported.
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Genetic Testing
Genetic testing can confirm a diagnosis, guide treatment decisions, and identify family members who may be at risk.
There is no single gene that causes MS. You can't take a test and get a yes-or-no answer the way you can with Huntington's or cystic fibrosis. What genetics do affect is your risk of getting MS, how the disease progresses, and how well you respond to treatment. Over 200 gene variants have been linked to MS susceptibility, and this section covers the ones that matter most for patients.
This is the strongest known genetic risk factor for MS. Carrying this gene variant (an HLA class II allele) roughly triples your risk. HLA typing (a blood test) is available at most labs and is sometimes used to help confirm a diagnosis when symptoms could be MS or something else.
Researchers are building tools called polygenic risk scores (PRS) that add up hundreds of small genetic risk factors into a single number. These aren't used in clinics yet, but they may eventually help identify which family members of MS patients are at higher risk and could benefit from early monitoring.
Your genes can influence how well MS drugs work for you and what side effects you experience. Researchers are studying whether genetic markers can predict which patients will respond best to specific treatments like interferons, natalizumab, and anti-CD20 therapies (drugs like ocrelizumab). Some clinical trials now include genetic sub-studies to explore this.
Several other conditions can look like MS on an MRI or in the exam room. Genetic testing can help rule out these mimics, including NMOSD (neuromyelitis optica), hereditary spastic paraplegia, CADASIL (a genetic stroke disorder), and certain leukodystrophies (white matter diseases). If your doctor isn't sure whether it's MS, a targeted genetic panel may help clarify.
If a close family member has MS, your risk is higher than average but still relatively low. Children and siblings of someone with MS have roughly a 2-4% lifetime risk, compared to about 0.1% in the general population. Environmental factors like vitamin D levels, Epstein-Barr virus exposure, and smoking interact with genetic risk, so genetic counseling can help put the numbers in context for your family.
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Trusted Multiple Sclerosis Resources
Reputable organizations and medical references for learning more about Multiple Sclerosis, including disease registries, foundation resources, and clinical guidelines.