What Is Multiple Sclerosis?

Medically Reviewed by Poonam Sachdev on February 25, 2024
10 min read

Multiple sclerosis (MS) happens when your immune system attacks myelin, the sheath around your nerve cells. Without this outer shell, your nerves become damaged and cause communication problems between your brain and the rest of your body.

MS is a chronic, or long-lasting, disease that can affect your brain, spinal cord, and the optic nerves in your eyes. It can cause problems with vision, balance, muscle control, and other basic body functions. 

The effects of MS vary from person to person. Some people have mild symptoms and don’t need treatment, while others have trouble getting around and doing daily tasks.

The damage means your brain can’t send signals through your body correctly. Your nerves also don’t work as they should to help you move and feel. As a result, you may have symptoms such as:

  • Trouble walking
  • Feeling tired
  • Muscle weakness or spasms
  • Blurred or double vision
  • Numbness and tingling
  • Sexual problems
  • Poor bladder or bowel control
  • Pain
  • Depression
  • Problems focusing or remembering

The first symptoms of multiple sclerosis often start between ages 20 and 40. Most people with MS have attacks, also called relapses, when the condition gets noticeably worse. They’re usually followed by times of recovery when symptoms improve. For other people, the disease continues to get worse over time.

In recent years, scientists have found many new treatments that can often help prevent relapses and slow the disease’s effects.

There are three main types of MS:

Relapsing-remitting MS (RRMS)

It’s the most common type of MS. About 85% of people with MS get this diagnosis. With RRMS, you tend to get temporary flare-ups. These are called relapses. If you have RRMS, you’re very likely to get worsening symptoms during an attack. 

After the flare-up, you go through a phase of remission, which means you may return to baseline without symptoms or may have an increase in disability after a relapse (called RRMS with worsening). However, your condition doesn’t get worse during remission. 

Primary-progressive MS (PPMS)

If you have PPMS, your MS symptoms tend to slowly worsen after you’re diagnosed. But you don’t get specific periods of relapses or remission. About 10% of people with MS get diagnosed with PPMS.

Secondary-progressive MS (SPMS)

With SPMS, your symptoms steadily get worse over time. You might develop this type after you develop early RRMS symptoms. Studies don’t clearly show whether medications can slow down your condition from getting worse.

Symptoms may differ for each person. And as the condition progresses or gets worse, you might see new symptoms. The first signs of MS usually include vision changes. This is also known as optic neuritis. Issues may include:

  • Complete or partial loss of vision (which usually happens in one eye at a time)
  • Pain when you move your eyes
  • Blurry vision
  • Double vision

Other common early signs of multiple sclerosis that you may have are:

  • Numbness and tingling
  • Fatigue
  • Loss of balance
  • Dizziness
  • Stiffness
  • Spasms
  • Tremors
  • Pain
  • Bladder problems
  • Bowel trouble
  • Thinking and memory problems

Doctors don’t know for sure what causes MS, but many things seem to make the disease more likely. People with certain genes may have higher chances of getting it. Smoking also may raise the risk.

Some people may get MS after they’ve had a viral infection, such as the Epstein-Barr virus or the human herpesvirus 6, as it makes their immune system stop working normally. The infection may trigger the disease or cause relapses. Scientists are studying the link between viruses and MS, but they don’t have a clear answer yet.

Some studies suggest that vitamin D, which you can get from sunlight, may strengthen your immune system and protect you from MS. For some people with higher chances of getting the disease, moving to sunnier regions seems to lower their risk.

It is unknown what causes MS. But you may be more likely to get it if you:

  • Are assigned female at birth (AFAB)
  • Are in your 20s, 30s, or 40s
  • Don’t spend a lot of time in the sun
  • Live in a cloudy, rainy, or darker climate
  • Smoke
  • Are fighting a viral infection, such as the Epstein-Barr virus
  • Have a family history of MS

Ethnicity also plays a role. Rates of developing MS are highest among Black people, followed by white and Hispanic people. Asian and Native American individuals are at the lowest risk. People who have higher levels of vitamin D, which include people who live in sunnier climates and spend more time outdoors, are less likely to get MS.

It can be hard to diagnose MS since its symptoms can be the same as those of many other nerve disorders. If your doctor thinks you have it, they’ll want you to see a specialist who treats the brain and nervous system, called a neurologist. They’ll ask you about your medical history and check you for key signs of nerve damage in your brain, spinal cord, and optic nerves.

MS tests

There’s no single test that can prove you have MS. Your doctor will use a few different ones to check you. These may include:

  • Evoked potential tests, which record the electrical signals produced by your nervous system in response to stimuli.
  • Blood tests to rule out diseases that cause similar symptoms, such as Lyme disease and HIV.
  • Tests to check your balance, coordination, vision, and other functions to see how well your nerves are working.
  • A test that makes detailed pictures of the structures in your body (specifically your brain or spinal cord ), called an MRI.
  • Analysis of cerebrospinal fluid (CSF), the liquid that cushions your brain and spinal cord. This will be done through a lumbar puncture or spinal tap. People with MS usually have specific proteins in their CSF.
  • Optical coherence tomography (OCT), a test used to detect changes in the retina, which could warn of brain atrophy.

Multiple sclerosis vs. myasthenia gravis

MS and myasthenia gravis (MG) are both disorders of the immune system that cause weakness. MS impacts the central nervous system and more parts of the body, including vision, balance, and coordination. On the other hand, the primary symptom of MG is facial weakness that worsens with activity. Muscle weakness with MG can also extend to other parts of the body. Some people have both MS and MG.

There is no cure for MS, but several treatments can improve how you feel and keep your body working well.

Your doctor can also prescribe drugs that may slow the course of the disease, prevent or treat attacks, ease your symptoms, or help you manage the stress that can come with the condition.

Drugs that may slow your MS or help nerve damage include:

  • Alemtuzumab (Lemtrada) 
  • Beta interferon (Avonex, Betaseron, and Rebif)
  • Cladribine (Mavenclad)
  • Dalfampridine (Ampyra)
  • Dimethyl fumarate (Tecfidera)
  • Diroximel fumarate (Vumerity)
  • Fingolimod (Gilenya)
  • Glatiramer (Copaxone)
  • Mitoxantrone (Novantrone)
  • Monomethyl fumarate (Bafiertam)
  • Natalizumab (Tysabri)
  • Ocrelizumab (Ocrevus)
  • Ofatumumab (Kesimpta)
  • Ozanimod (Zeposia)
  • Ponesimod (Ponvory)
  • Siponimod (Mayzent)
  • Teriflunomide (Aubagio)
  • Ublituximab-xiiy (Briumvi)

Your doctor may give you steroids to make your MS attacks shorter and less severe. You can also try other drugs, such as muscle relaxants, tranquilizers, or botulinum toxin (Botox), to ease muscle spasms and treat some of the other symptoms.

A physical therapist can teach you exercises that will keep up your strength and balance and help you manage fatigue and pain. An occupational therapist can teach you new ways to do certain tasks to make it easier to work and take care of yourself. If you have trouble getting around, a cane, walker, or braces can help you walk more easily.

Along with treatment, you can do other things to ease your MS symptoms. Get regular exercise and avoid too much heat to boost your energy. Ask your doctor about trying yoga to ease fatigue or stress. Take care of your emotional health, too. It’s OK to ask family, friends, or a counselor for help with any stress or anxiety you may feel. Support groups are also great places to connect with other people living with MS.

If you have MS, you may deal with any of these complications:

  • Epilepsy
  • Muscle stiffness
  • Paralysis (usually in the legs)
  • Mental changes including forgetfulness or mood swings
  • Interruptions in or reduction of mobility
  • Vertigo
  • Trouble swallowing
  • Tremors
  • Urinary tract infections
  • Constipation

MS can not be entirely prevented. It’s caused by a variety of known and unknown factors, many of which are out of your control. But there are ways to reduce your risk. Lifestyle habits such as getting adequate vitamin D, maintaining a healthy weight, living in a sunny climate, spending time outside, reducing stress, and not smoking may help prevent MS.

You can do a few things that may ease multiple sclerosis symptoms:

Prioritize sleep. Make sure you’re getting quality sleep and enough of it. Keep consistent sleep and wake times to maintain good sleep hygiene. If you have obstructive sleep apnea or another sleep disorder, talk to your doctor about treating it.

Eat well. Nutrition plays a role in health, so a balanced diet can help you feel your best. Eat whole grains instead of refined grains. Avoid or limit processed foods and added sugar. Eat plenty of fruits and veggies.

Exercise regularly. Getting active regularly may enhance your strength, balance, and coordination.

Keep cool. Symptoms can get worse if your body temperature is higher. Avoid the heat, or wear clothing that helps you stay cool.

Destress. Stress can trigger symptoms, so find a way to relieve stress that works for you. Yoga, meditation, or massage may help.

Avoid smoking. This is linked to a wide range of diseases and conditions. Smoking can also make MS symptoms get worse more quickly. 

Get regular care. See your doctor or health care professional regularly to keep tabs on symptoms. Ask for information on new and upcoming treatments.

Customize your environment. Make whatever modifications you need in your living spaces to accommodate your multiple sclerosis. That may mean things including decluttering, adding grab bars, and other adjustments.

Anticipate possible changes. MS may change how much you can work (and it can stop you from being able to work). As a result, you may earn less (or not be able to earn an income at all). In one study, people with MS who had lower socioeconomic status became disabled faster. Participants were more likely to experience SPMS -- which means their neurologic function got worse -- more quickly, too.

Seek support. Connecting with others who have MS may give you the mental and emotional support needed to live well.

Because there’s no cure for MS, your doctor will focus on treating your symptoms. Over the past 20 years, new treatments have greatly improved the quality of life for those with the disease. These treatments not only help with symptoms, but they can also slow the progression of MS.

About half of those with MS will still be able to walk on their own 15 years after diagnosis. The rest will need a wheelchair or other aids. On average, it takes 33 years for individuals with MS to progress to serious disability, such as confinement to bed.

Most people with MS have close to a normal life expectancy. Though in some serious cases, people with MS can die early from pneumonia or other infections related to their disease, most people die from other ailments. Overall, the life expectancy of someone with MS is only about 5% less than that of a normal healthy adult.

In general, symptoms and disabilities don’t worsen significantly from those you have in the first 5 years after diagnosis. Still, it’s hard to know what path the disease will take in any particular case.

Careful and consistent monitoring and treatment of MS with your medical team is the best way to keep your symptoms at bay and slow the progression of the disease.

There are many resources available for people who are diagnosed with MS and their families and caregivers. The National Multiple Sclerosis Society has a lot of information about getting help, including “MS Navigators” who can answer questions and connect you with support services. Your doctor can also help you find local resources.

Multiple sclerosis is a complex, lifelong disease. Its causes are not fully understood, but there are ways to treat your symptoms and manage the disease's impact on your life. If you've been diagnosed, contact your doctor with any questions and for help accessing resources and support.

  • How common is multiple sclerosis?

    MS is the most common neurological disease to affect young adults. Nearly 1.8 million people have MS worldwide.

  • Can you live alone if you have MS?

    It depends on how advanced your symptoms are. There is a range of assistive technology and ways to modify your home environment that can help you maintain your independence. But everyone's symptoms are different. People with advanced MS may need help from a professional caregiver to maintain a good quality of life.