Multiple sclerosis (MS) is a condition in which the immune system attacks the brain and spinal cord. Common first symptoms include loss of vision in one eye with painful eye movements, double vision, numbness or weakness that spreads upwards, and problems with balance. Symptoms usually develop over more than a day and often improve over days or weeks.
Diagnosis is made by a consultant neurologist, using your history, an examination, an MRI scan and sometimes a lumbar puncture. Doctors in the UK now follow the 2024 revised McDonald criteria, according to NICE.
There is no cure. But disease-modifying therapies (DMTs) reduce relapses and new MRI lesions, and some slow disability. They range from tablets and self-injections to infusions such as natalizumab and ocrelizumab. The most effective drugs carry more serious risks, including PML, a rare brain infection. In Ireland and the UK, most DMTs are prescribed by specialist MS services and funded publicly, but which drugs and for whom varies.
NICE guideline NG220 lists the most common presenting symptoms:
NICE adds that people with MS are often under 50. Their symptoms usually evolve over more than 24 hours, may last days or weeks and then improve, and come without fever or infection.
The NHS lists other common symptoms: extreme tiredness, muscle stiffness and spasms, bladder problems, problems with memory or concentration, and sexual problems.
Most people with these symptoms do not have MS. NICE says not to routinely suspect MS from fatigue, depression, dizziness or vague sensory symptoms alone, without focal neurological signs. Our guide to pins and needles covers the more common causes of tingling.
The NHS says MS is more likely if you are aged 20 to 50, a woman, or have a parent or sibling with MS. People who smoke are about twice as likely to develop it. Past Epstein-Barr virus infection, the cause of glandular fever, is also linked.
NICE says to refer anyone suspected of having MS to a consultant neurologist. The GP should first confirm it is a neurological episode and rule out more common causes.
Diagnosis combines:
NICE's guideline was amended in 2026 to follow the 2024 revised McDonald criteria. If the criteria are not met but MS is still suspected, NICE says to plan a review.
In Ireland, referral is usually through your GP to a hospital neurology service. Our guide to getting referred to a neurologist in Ireland explains the public and private routes.
The NHS describes three main patterns:
Neurologists increasingly see these as overlapping parts of one disease. Our page on MS, vitamin D and omega-3 explains that shift and covers the supplement evidence.
NICE says relapses that affect everyday activities should be assessed and treated as early as possible, within 14 days. Infection, especially urinary and chest infection, should be ruled out first, because infection can make symptoms flare without a true relapse.
Treatment is usually a short course of high-dose steroid tablets, with steroid drips for people who cannot take tablets or need hospital care. Not every relapse needs steroids. Steroids speed recovery from a relapse but are not a long-term treatment.
DMTs work on the immune system to reduce attacks. They are started and supervised by MS specialists. Choosing one is a shared decision based on how active your MS is, your other health conditions, pregnancy plans, and how you feel about risk and routine.
NICE has appraised each drug separately. Its guideline lists twelve options for active relapsing-remitting MS. It lists further options for highly active MS, for rapidly evolving severe MS and for secondary progressive MS with activity. For early primary progressive MS with inflammatory activity on imaging, NICE recommends ocrelizumab.
NICE also says not to offer vitamin D solely to treat MS, or omega-3 or omega-6 fatty acids to treat MS.
Trials show the higher-efficacy drugs reduce relapses and new lesions substantially. Their effect on disability is real but smaller. Our vitamin D and omega-3 page gives the main trial results for ocrelizumab, natalizumab and siponimod, so we do not repeat them here.
Natalizumab (Tysabri) is a highly effective drug for active relapsing MS. Its main risk is progressive multifocal leukoencephalopathy (PML). This is a rare brain infection caused by the JC virus. It can be fatal or cause severe disability.
The UK product information names three risk factors:
People with all three have a significantly higher risk. In JC-antibody-positive people without prior immunosuppressants, the antibody level (index) is linked to the level of risk.
What this means in practice:
Tell your MS team quickly about any new or worsening symptoms, such as weakness, clumsiness, changes in vision, speech or thinking. These can look like an MS relapse.
Ocrelizumab (Ocrevus) is given as an infusion every 6 months after the first doses. According to its UK product information, PML has been seen very rarely with anti-CD20 drugs, mostly in people with other risk factors. Before starting, you will be screened for hepatitis B, because these drugs can reactivate it. Infusion reactions are common, so medicines are given beforehand to reduce them.
NICE says MS should not stop people from planning a family. Some DMTs must be stopped or timed carefully before conception. NICE says people on DMTs should tell their team straight away if they are trying to become pregnant or become pregnant.
NICE recommends:
Fatigue is one of the most common and disabling symptoms. NICE says it can be brought on by heat or by physical and emotional stress. Your team should also check for treatable contributors such as poor sleep, infections, anaemia, thyroid problems, depression or medication side effects.
Depression and anxiety are common with MS and are treatable. If you have thoughts of suicide, call Samaritans free on 116 123 in Ireland or the UK, or text 50808 in Ireland. In an emergency, call 112 or 999.
Sources: NCPE natalizumab, NCPE ocrelizumab (relapsing), NCPE ocrelizumab (primary progressive), NCPE ocrelizumab subcutaneous, NCPE ofatumumab, NCPE ublituximab, NICE NG220 and the EMA.
In the US, the FDA first approved natalizumab in November 2004 and ocrelizumab in March 2017, according to Drugs@FDA.
Ireland. DMTs are prescribed by hospital neurology services. In several cases, the NCPE advised against reimbursement at the original price, and the HSE then approved the drug after confidential price negotiations. We did not check the status of every DMT. Ask your neurologist which options are funded for your type of MS.
England. NICE technology appraisals mean the NHS must fund recommended drugs for the eligible group. NHS England also uses a treatment algorithm. NICE says fingolimod is an NHS England option instead of natalizumab for rapidly evolving severe MS in people at high PML risk.
Scotland, Wales and Northern Ireland. We did not check separate decisions.
Clinical trials. We have not listed trials. Ask your MS team if you are interested in research.
No. The NHS says MS cannot currently be cured, but treatment can often help manage it. DMTs reduce relapses and new lesions, and some slow disability.
It depends on three factors: JC virus antibodies, treatment beyond 2 years, and previous immunosuppressant use. Your team estimates your risk from these and from your antibody level, and monitors you with blood tests and MRI.
NICE says not to offer vitamin D solely to treat MS, and not to offer omega-3 or omega-6 to treat MS. We cover that evidence on our vitamin D and omega-3 page.
NICE says relapses that affect daily activities should be assessed and offered treatment as early as possible, within 14 days of symptoms starting. Contact your MS team or GP.
This article is general information, not medical advice. Talk to your GP or MS team about your own situation.
Reviewed by: Proco Team
Last updated: November 2026