What is multiple sclerosis?

Multiple sclerosis, also referred to as “MS,” is a neurological disorder affecting the nerves of the brain and spinal cord. MS is thought to be an “autoimmune” disease, which means that a person’s own immune system is attacking their body. This attack damages the protective covering to the nerves (myelin) and eventually the nerves (axons) as well.

MS is most often diagnosed in young adults, and symptoms can range from visual changes, numbness, and vertigo, to bladder and bowel problems, weakness, and spasticity (muscle tightness), among other symptoms. Individuals may also experience emotional difficulties, such as depression, or cognitive issues, such as forgetfulness. For most people with early MS, symptoms tend to flare up (“relapse”) and subside (“remit”) for long periods of time.

For more information, please visit our MS Overview section of MSAA’s website.

What causes MS?

While we know that MS is not contagious, an exact cause of this disease has yet to be determined. Most researchers believe that more than one factor is involved in the development of MS. One popular theory involves a slow-acting virus, such as Epstein-Barr virus (EBV) or measles, which could remain dormant (inactive) for many years before contributing to the development of MS in genetically susceptible people.

MS is not hereditary, but having more than one family member diagnosed with MS is not uncommon. Numerous studies have shown that this increased risk among family members is a result of sharing DNA, and not a result of sharing the same environment. Therefore, genes play a role to some degree.

Additionally, researchers are now looking at a vitamin D deficiency (vitamin D may be derived from both sunlight and diet), along with the types and amounts of fat intake in one’s diet, as possible contributing factors to MS. Cigarette smoking is another factor that can be involved in the development of MS. It not only increases one’s risk of developing MS, but also increases the rate of progression of one’s MS.

For more information, please visit our Possible Causes of MS section of MSAA’s website.

Is MS fatal? Can MS be treated?

Only a small percentage of patients experience a rapidly progressive type of MS, which may cause more significant health issues early in the disease. Some individuals, particularly those who are significantly inactive, may experience the typical complications of a prolonged chronic illness (such as infection or pneumonia). Additionally, a recent study has shown that for individuals with relapsing forms of MS, those who begin treatment early with a disease-modifying therapy and stay on the therapy, may live longer than those who are not on treatment.

With various adjustments made along the way, most individuals with MS may look forward to a full and productive life. As for anyone, other health factors play a role in determining an individual’s quality of life as well as life expectancy. Examples of such health factors include diet, exercise, whether or not someone smokes, alcohol consumption, and family history of disease.

While no cure for MS has been found, more than 25 FDA-approved, disease-modifying therapies are now available for the long-term treatment of MS. These have been shown to slow disease activity by reducing the number and severity of MS flare-ups, reducing the number and size of lesions in the central nervous system, and for many, slowing disease progression. Treatments are now available for both relapsing as well as progressive forms of MS.

What type of doctor specializes in MS? How is MS diagnosed?

Since MS is a neurological condition, it is usually diagnosed and treated by a neurologist. Other professionals specializing in neurology in conjunction with another area of medicine – such as radiology (neuroradiologist), ophthalmology (neurophthalmologist), and psychology (neuropsychologist) — may also assist with one’s diagnosis and ongoing treatment plan.

Because the symptoms of early MS can come and go, and because a single test is not yet available to determine if one has MS, getting a diagnosis is often difficult. Several appointments and tests (to exclude other conditions) may be necessary.

Tools used to help diagnose and evaluate MS include:

  • Magnetic Resonance Imaging (MRI)
  • Magnetic Resonance Spectroscopy (MRS)
  • Lumbar Puncture (spinal tap)
  • Evoked Potentials (EP) tests
  • Expanded Disability Status Scale (EDSS)
  • Functional System (FS) scale
  • MS Functional Composite (MSFC) scale

For more information, please see the “Diagnosing MS and Evaluating Disease Activity” section of our website.

Who gets MS? How many people have MS?

Most people with MS experience their first symptoms and are diagnosed between the ages of 20 and 50. Previously, MS in younger children was extremely rare. Referred to as “Pediatric MS,” the diagnosis of MS at a young age is on the rise. Researchers do not know if this is an indication of people developing MS at an earlier age, or if this is a result of greater disease awareness and more sensitive diagnostic procedures. Additionally, while still less-common, people over the age of 50 are now being diagnosed more frequently. People in their 50s, 60s, and even 70s may receive a diagnosis of MS, although this is often after years of unexplained symptoms.

Women are two to three times more likely to develop MS versus men. Caucasians, especially those of European or Scandinavian ancestry, are at a greater risk of MS than those of African or Hispanic heritage, although these latter numbers are on the rise as both awareness and access to medical care increase.

Individuals growing up in regions closer to the equator have a lower incidence of MS. The rate of MS increases as distance from the equator increases. This environmental factor may relate to diet, exposure to sunlight, and/or other lifestyle traits.

Nearly one million individuals are living with MS in the United States. This new prevalence figure was published in 2019 and is more than double the previous estimate of 400,000 affected people in the United States. Current estimates bring the worldwide MS population to nearly three million.

The North American Research Committee on Multiple Sclerosis (NARCOMS) has an MS registry with an active database of more than 42,000 individuals with MS. If you are interested in learning more or becoming a part of this registry, please visit

For more information on Who Gets MS, please refer to this section under the “MS Overview” section of MSAA’s website.

Does MS or its treatments pose any risks to becoming pregnant?

Many of those diagnosed with MS are young adults with plans of having children at some point in their future. The good news is that MS does not affect fertility, and pregnancies progress “normally” (that is, having the same benefits and risks as someone without MS).

For most women with MS, MS symptoms often stabilize or improve during pregnancy. Unfortunately, 20-to-40 percent of women have a relapse following delivery, so new mothers will need to plan for more rest and assistance during the first few months. Disease progression and long-term risk of additional relapses are not affected by pregnancy.

Some of the medications taken for MS can affect fertility or increase the risk of miscarriage and are transmitted in breast milk. Individuals considering pregnancy should discuss their medications with their neurologist in advance. Some medications may need to be discontinued for a few months before attempting to become pregnant.

Having a child is an important decision for any person or couple. With MS, parents need to consider that fatigue and other symptoms may affect the amount of activity the mother may be able to perform with the child or children in their younger years. Assistance from others – such as family and friends – may be needed at certain times. Before making the commitment, individuals and couples may want to discuss these pregnancy-related issues with their healthcare team.

Can I inherit MS?

Many people ask if MS may be inherited. While MS in not hereditary, individuals may be “genetically susceptible,” increasing their risk of MS. This risk is slight, with only a 3 to 4% percent chance of a child (with a parent who has MS) being diagnosed with MS sometime in his or her future.

Researchers believe that genetics are only one piece to the puzzle, and other factors (such as common viruses, environment, diet, etc.) are also necessary to develop MS. Additionally, MS research is making great strides toward identifying causes and fine-tuning effective treatments.

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