What Is Multiple Sclerosis?

Medically Reviewed by Christopher Melinosky, MD on February 03, 2023
8 min read

Multiple sclerosis, or 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 are often different for everyone who has the disease. Some people have mild symptoms and don’t need treatment. Others will 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 like:

  • 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 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 – meaning 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 from the time 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. This usually happens in one eye at a time.
  • Pain when you move your eyes
  • Blurry vision
  • Double vision

Other common early signs that you may likely have are:

  • Numbness and tingling
  • Fatigue
  • Loss of balance
  • Dizziness
  • Stiffness
  • Spasms
  • Tremors
  • Pain
  • Bladder problems
  • Bowel trouble
  • Troubling thinking
  • Memory issues

Doctors don’t know for sure what causes MS, but there are many things that 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 -- like the Epstein-Barr virus or the human herpesvirus 6 -- that 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. Some people with higher chances of getting the disease who move to sunnier regions seem to lower their risk.

It can be hard to diagnose MS since its symptoms can be the same as 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.

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, like Lyme disease and HIV.
  • Checks of 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 the liquid that cushions your brain and spinal cord called cerebrospinal fluid (CSF). This will be done through a lumbar puncture or spinal tap. People with MS usually have specific proteins in their CSF.
  • OCT (optical coherence tomography) used to detect changes in the retina, which could warn of brain atrophy

There is no cure for MS, but a number of 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)
  • Cladribrine (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, like 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 like forgetfulness or mood swings
  • Interruptions in or reduction of mobility
  • Vertigo
  • Trouble swallowing
  • Tremors
  • Urinary tract infections
  • Constipation

You can do a few things that may ease 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 care regularly. 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 needed in your living spaces to accommodate your MS. That may mean decluttering, adding grab bars, and the like.

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 secondary progressive multiple sclerosis (SPMS) -- that 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, 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. The average time to serious disability like confinement to bed is 33 years.

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 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.