What is multiple sclerosis (MS)?

Multiple sclerosis (MS) is a chronic illness involving your central nervous system (CNS). The immune system attacks myelin, which is the protective layer around nerve fibers.
This causes inflammation and scar tissue, or lesions. This can make it hard for your brain to send signals to the rest of your body. See illustrations that show the physiological changes associated with MS.

What are the symptoms of MS?

People with MS experience a wide range of symptoms. Due to the nature of the disease, symptoms can vary widely from person to person. They can also change in severity from year to year, month to month, and even day to day.
Two of the most common symptoms are fatigue and difficulty walking.


Around 80 percent of people with MS report having fatigue. Fatigue that occurs with MS can become debilitating, affecting your ability to work and perform everyday tasks.

Difficulty walking

Difficulty walking can occur with MS for a number of reasons:
  • numbness in your legs or feet
  • difficulty balancing
  • muscle weakness
  • muscle spasticity
  • difficulty with vision
  • overwhelming fatigue
Difficulty walking can also lead to injuries due to falling.

Other symptoms

Other fairly common symptoms of MS include:
  • acute or chronic pain
  • tremor
  • cognitive issues involving concentration, memory, and problem-solving skills
The condition can also lead to speech disorders. Learn more about the symptoms of MS.

What are the types of MS?

Types of MS include:

Clinically isolated syndrome (CIS)

Clinically isolated syndrome (CIS) involves one episode of symptoms lasting at least 24 hours. These symptoms are due to demyelination in your CNS.
There are two types of episodes: monofocal and multifocal. A monofocal episode means one lesion causes one symptom. A multifocal episode means you have more than one lesion and more than one symptom.
Although these episodes are characteristic of MS, they aren’t enough to prompt a diagnosis.
If lesions similar to those that occur with MS are present, you’re more likely to receive a diagnosis of relapsing-remitting MS (RRMS). If these lesions aren’t present, you’re less likely to develop MS.

Relapsing-remitting MS (RRMS)

Relapsing-remitting MS (RRMS) involves clear relapses of disease activity followed by remissions. During remission periods, symptoms are mild or absent and there’s no disease progression.
RRMS is the most common form of MS at onset and accounts for about 85 percent of all cases.

Primary progressive MS (PPMS)

If you have primary progressive MS (PPMS), neurological function becomes progressively worse from the onset of your symptoms. However, short periods of stability can occur. The terms “active” and “not active” are used to describe disease activity.
Progressive-relapsing MS (PRMS) was a term previously used to describe progressive MS with clear relapses. This is now categorized as PPMS.

Secondary progressive MS (SPMS)

Secondary progressive MS (SPMS) occurs when RRMS transitions into the progressive form. You may still have noticeable relapses in addition to disability or gradual worsening of function.

The bottom line

Your MS may change and evolve, but you can only have one type of MS at a time. Find out more about the different types of MS.

How is MS treated?

No cure is available for MS, but multiple treatment options exist.

Disease-modifying therapies (DMTs)

Disease-modifying therapies (DMTs) are designed to slow disease progression and lower your relapse rate.
Self-injectable disease-modifying medications for RRMS include glatiramer acetate (Copaxone)and beta interferons, such as:
  • Avonex
  • Betaseron
  • Extavia
  • Plegridy
  • Rebif
Oral medications for RRMS include:
  • dimethyl fumarate (Tecfidera)
  • fingolimod (Gilenya)
  • teriflunomide (Aubagio)
Intravenous infusion treatments for RRMS include:
  • alemtuzumab (Lemtrada)
  • natalizumab (Tysabri)
  • mitoxantrone hydrochloride (only available in generic form), which is for severe MS only
In 2017, the Food and Drug Administration (FDA) approved the first DMT for people with PPMS. This injectable drug is called ocrelizumab (Ocrevus), and it can also be used to treat RRMS.
Not all MS drugs will be available to or appropriate for every person. Talk to your doctor about which drugs are currently on the market and the risks and benefits of each one.

Other drugs

Your doctor can prescribe corticosteroids, such as methylprednisolone (Medrol) and prednisone (Prednisone Intensol, Rayos) to treat relapses.
Other treatments may also ease your symptoms and improve your quality of life. Because MS is different for everyone, treatment depends on your specific symptoms. For most, a flexible approach is necessary. Get more information on treatments for MS.

What are the early signs of MS?

MS can develop all at once, or the symptoms can be so mild that you easily dismiss them. Three of the most common early symptoms of MS are:
  • Numbness and tingling that affects the arms, legs, or one side of your face. These sensations are similar to the pins-and-needles feeling you get when your foot falls asleep. However, they occur for no apparent reason.
  • Uneven balance and weak legs. You may find yourself tripping easily while walking or doing some other type of physical activity.
  • Double vision, blurry vision, or partial vision loss. These can be an early indicator of MS. You may also have some eye pain.
It isn’t uncommon for these early symptoms to go away only to return later. You may go weeks, months, or even years between flare-ups.
These symptoms can have many different causes. Even if you have these symptoms, it doesn’t necessarily mean that you have MS. Discover more early signs of MS.

What causes MS?

If you have MS, the protective layer of myelin around your nerve fibers becomes damaged.
It’s thought that the damage is the result of an immune system attack. Researchers think there could be an environmental trigger such as a virus or toxin that sets off the immune system attack.
As your immune system attacks myelin, it causes inflammation. This leads to scar tissue, or lesions. The inflammation and scar tissue disrupt signals between your brain and other parts of your body.
MS isn’t hereditary, but having a parent or sibling with MS raises your risk slightly. Scientists have identified some genes that seem to increase susceptibility to developing MS. Find out more about the possible causes of MS.

How is MS diagnosed?

Your doctor will need to perform a neurological exam, a clinical history, and a series of other tests to determine if you have MS.
Diagnostic testing may include the following:
  • MRI scan. Using a contrast dye with the MRI allows your doctor to detect active and inactive lesions throughout your brain and spinal cord.
  • Visual evoked potentials test. This test requires the stimulation of nerve pathways to analyze electrical activity in your brain. In the past, brainstem auditory and sensory evoked potential tests were also used to diagnose MS.
  • Spinal tap (lumbar puncture). Your doctor may use a spinal tap to find abnormalities in your spinal fluid. It can help rule out infectious diseases.
  • Blood tests. Doctors use blood tests to eliminate other conditions with similar symptoms.
The diagnosis of MS requires evidence of demyelination occurring at different times in more than one area of your brain, spinal cord, or optic nerves.
It also requires ruling out other conditions that have similar symptoms. Lyme diseaselupus, and Sjögren’s syndrome are just a few examples. Learn more about the tests used to diagnose MS.

What’s it like to live with MS?

Most people with MS find ways to manage their symptoms and function well.


Having MS means you’ll need to see a doctor experienced in treating MS.
If you take one of the DMTs, you’ll have to make sure you adhere to the recommended schedule. Your doctor may prescribe other medications to treat specific symptoms.

Diet and exercise

well-balanced diet, low in empty calories and high in nutrients and fiber, will help you manage your overall health.
Regular exercise is important for physical and mental health, even if you have disabilities. If physical movement is difficult, swimming or exercising in a swimming pool can help. Some yoga classes are designed just for people with MS.

Other complementary therapies

Studies regarding the effectiveness of complementary therapies are scarce, but that doesn’t mean they can’t help in some way.
The following may help you feel less stressed and more relaxed:
  • meditation
  • massage
  • tai chi
  • acupuncture
  • hypnotherapy
  • music therapy

The bottom line

MS is a lifelong condition. You’ll face unique challenges that can change over time.
You should focus on communicating concerns with your doctor, learning all you can about MS, and discovering what makes you feel your best.
Many people with MS even choose to share their challenges and coping strategies through in-person or online support groups. See what 11 public figures have to say about navigating life with MS.

What are the dietary recommendations for people with MS?

Diet hasn’t been shown to have an impact on the nature of the disease, but it can help with some of your challenges. If you’re fatigued, for instance, a diet high in fats and simple carbohydrates won’t help.

What to eat

Your diet should mainly consist of:
  • a variety of fruits and vegetables
  • lean sources of protein, such as fish and skinless poultry
  • whole grains and other sources of fiber
  • nuts
  • legumes
  • low-fat dairy products
  • adequate amounts of water and other fluids
The better your diet, the better your overall health. You’ll not only feel better in the short term, but you’ll be laying the foundation for a healthier future. Explore the relationship between diet and MS.

What to limit or avoid

You should limit or avoid:
  • saturated fat
  • trans fat
  • red meats
  • foods and beverages high in sugar
  • foods high in sodium
  • highly processed foods
If you have other medical conditions, ask your doctor if you should follow a special diet or take any dietary supplements. Specialized diets such as the ketopaleo, or Mediterranean diets may help with some of the challenges faced by people with MS.
Read food labels. Foods that are high in calories but low in nutrients won’t help you feel better or maintain a healthy weight. Check out these additional tips for eating an MS-friendly diet.

What are the statistics on MS?

According to the National Multiple Sclerosis Society, there hasn’t been a scientifically sound national study on the prevalence of MS in the United States since 1975. In a 2017 study, however, the Society estimated that around 1 million Americans have MS.
Other things you should know:
  • MS is the most widespread neurological condition disabling young adults worldwide.
  • Most people are between the ages of 20 and 50 at the time of their diagnosis.
  • Overall, MS is more common in women than men. According to the National Multiple Sclerosis Society, RRMS is two to three times more common in women than men, and PPMS rates in women and men are roughly equal.
  • Rates of MS tend to be lower in places that are closer to the equator. This may have to do with sunlight and vitamin D exposure. People who relocate to a new location before age 15 generally acquire the risk factors associated with the new location.
  • Data from 1999 to 2008 showed that direct and indirect costs of MS were between $8,528 and $54,244 per year. Current DMTs for RRMS can cost up to $60,000 a year. Ocrelizumab (Ocrevus) costs $65,000 a year.
Canadians have the highest rate of MS in the world. Check out more MS facts and statistics here.

What are the effects of MS?

The lesions from MS can appear anywhere in your CNS and affect any part of your body.

Mobility issues

As you age, some disabilities from MS may become more pronounced. If you have mobility issues, falling may put you at an increased risk of bone fractures. Having other conditions such as arthritis and osteoporosis can complicate matters.

Other issues

One of the most common symptoms of MS is fatigue, but it’s not uncommon for people with MS to also have:
  • depression
  • anxiety
  • some degree of cognitive impairment

The bottom line

Mobility issues can lead to a lack of physical activity, which can cause other health problems. Fatigue and mobility issues may also have an impact on sexual function. Discover more effects of MS.

What is the prognosis for people with MS?

It’s almost impossible to predict how MS will progress in any one person.
About 10 to 15 percent of people with MS have only rare attacks and minimal disability ten years after diagnosis. This is sometimes called benign MS.
About half of people with MS use a cane or other form of assistance 15 years after receiving an MS diagnosis. At 20 years, about 60 percent are still ambulatory and less than 15 percent need care for their basic needs.

MS type

Progressive MS generally advances faster than RRMS. People with RRMS can be in remission for many years. A lack of disability after five years is usually a good indicator for the future.

Age and sex

The disease generally progresses faster in men than in women. It may also progress faster in those who receive a diagnosis after age 40 and in those who have a high relapse rate.

The bottom line

Your quality of life will depend on your symptoms and how well you respond to treatment. This rarely fatal but unpredictable disease can change course without warning.
Most people with MS don’t become severely disabled and continue to lead full lives. Take a closer look at the prognosis for people with MS.