Find a Doctor Find a Doctor
Time to see a specialist? Time to see a specialist?
We found [COUNT] Specialists
who treat [INTEREST]
near [LOCATION]
We found [COUNT] Specialists
who treat [INTEREST]
near [LOCATION]
[TELEHEALTH] offer Telehealth options.
More
Finding the Right Multiple Sclerosis Treatment

This content is created by Healthgrades and brought to you by an advertising sponsor. More

This content is created or selected by the Healthgrades editorial team and is funded by an advertising sponsor. The content is subject to the Healthgrades medical review process for accuracy, balance and objectivity. The content is not edited or otherwise influenced by the advertisers appearing on this page except with the possible suggestion of the broad topic area. For more information, read the Healthgrades advertising policy.

What Causes Multiple Sclerosis? Everything to Know

Medically Reviewed By Sharon Stoll, DO, MS

Multiple sclerosis (MS) occurs when the immune system attacks the central nervous system. While experts do not know exactly why this happens, they have identified numerous possible causes and triggers. According to the National Multiple Sclerosis Society, the possible causes of MS include environmental, immunological, and genetic factors.

These factors can trigger the immune system to cause inflammation in the central nervous system, which damages the myelin that protects the nerve fibers. This affects how your optic nerves, brain, and spinal cord work.

This guide discusses the possible causes of MS in more detail. It also looks at when you should contact a doctor, how to recognize the symptoms of MS, and more.

Genetics

Twins are lying next to each other.
Ole Spata/EyeEm/Getty Images

Genetic factors may make you more likely to develop MS. Studies found that an identical twin is about 25–30% Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source likely to have MS if their twin has the condition, which is about a 1 in 4 chance.

To put this into context, 1 in about 750–1,000 people in the general population will develop MS.

Researchers have identified about 200 genes that may make you more likely to develop MS. However, it is important to note that MS is not an inherited condition.

Research into the relationship between genetics and MS is ongoing.

Immunologic factors

Two main cells are involved in the immune system’s response to attacking the central nervous system: T cells and B cells.

T cells activate in the lymph system and enter the central nervous system through the blood vessels. They then release chemicals that can cause inflammation. This, in turn, damages the myelin and nerve fibers.

T cells can help activate B cells. B cells produce antibodies that can cause damage to the central nervous system.

Research into possible causes or triggers that activate the T cells and B cells is ongoing.

Infections

Infections may contribute to the development of MS. One 2018 article Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source suggests that infections can trigger the immune response that causes MS in individuals with a genetic disposition to the condition.

Certain proteins appear in the spinal fluid of people with nervous system conditions who have been affected by a virus. Around 90–95% of people with MS have the same or similar proteins, suggesting that infections might play a role in triggering MS.

Epstein-Barr virus

The Epstein-Barr virus, in particular, may increase your risk of MS. According to the National Institutes of Health, you may be up to 32 times more likely Trusted Source National Institutes of Health Governmental authority Go to source to develop MS following early exposure to the Epstein-Barr virus.

Geographical factors

Geographical location may increase your risk of developing MS.

MS is more common in areas farther away from the equator. However, the number of MS cases can vary among populations in the same geographical locations.

Moving between locations may alter the likelihood of developing MS. For example, if you are born far away from the equator but move closer to the equator in childhood, this may reduce your risk of MS.

Vitamin D deficiency due to being farther away from the equator may increase your risk of MS. More research into the relationship between MS and geography is needed to better understand whether location can impact the risk of MS.

Vitamin D

A 2018 study Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source found that having low vitamin D levels may increase your risk of developing MS.

Your doctor may recommend vitamin D as part of your treatment for MS. However, more research into the benefits of vitamin D for alleviating MS symptoms is necessary.

Learn about vitamin D.

Smoking

According to the Multiple Sclerosis Trust, you are more likely to develop MS if you smoke. One possible theory is that cigarette smoke damages the lungs’ endothelial cells.

Smoking can irritate the lungs, similar to irritation that can occur with exposure to smoke machines or air pollution.

If you have MS, smoking may worsen your disease progression, increasing your risk of needing a walker or wheelchair. If you smoke, consider contacting a doctor for recommendations about quitting.

Discover tips for quitting smoking.

Obesity

Obesity in early childhood and adolescence may be a contributing factor Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source to MS, particularly for people assigned female at birth.

In particular, obesity combined with other environmental or genetic factors may increase your risk of MS.

Also, inflammation that occurs as a result of obesity may contribute to or aggravate symptoms of MS.

How common is multiple sclerosis?

About 1 million people in the United States have MS. Most people receive an MS diagnosis between the ages of 20–50 years.

MS is three times more common in people assigned female at birth than males. This suggests that hormones may contribute to the development of the condition.

When should I see a doctor?

Contact your doctor as soon as you have concerns about multiple sclerosis.

They can perform tests to confirm the cause of your symptoms and talk with you about the right treatments.

Visit our Multiple Sclerosis Appointment Guide for more information.

What are the symptoms of multiple sclerosis?

In the early stage, MS typically affects vision. This can include:

  • blurred vision of one eye
  • double vision
  • color distortion

Find out more about .

Other symptoms of MS include:

  • difficulties with balance and coordination
  • muscle weakness
  • problems with standing or walking
  • numbness
  • speech problems
  • dizziness
  • memory problems
  • bladder urgency

Contact your doctor as soon as you experience MS symptoms. Receiving an accurate diagnosis as early as possible may help to alleviate symptoms and slow the condition’s progression.

Learn more

You can learn all about MS in our complete guide: What Is Multiple Sclerosis (MS)? Everything to Know.

You can also learn more about MS in the links below:

Summary

There is no individual cause of multiple sclerosis. Researchers have identified various immunological, environmental, and genetic factors that may contribute to the development of MS.

Infection, particularly from the Epstein-Barr virus, may increase your risk of MS. Other factors such as obesity, smoking, or having low vitamin D levels may increase your chances of developing MS.

Contact your doctor as soon as you have concerns about MS. They can perform a physical exam and order tests to help them reach an accurate diagnosis.

Was this helpful?
18
  1. Definition of MS. (n.d.). https://www.nationalmssociety.org/What-is-MS/Definition-of-MS
  2. Factors in distribution of MS. (n.d.). https://www.nationalmssociety.org/What-is-MS/Who-Gets-MS/Factors-in-Distribution-of-MS
  3. Gianfrancesco, M. A., et al. (2016). Obesity and multiple sclerosis susceptibility: A review. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5156319/
  4. Lazibat, I., et al. (2018). Multiple sclerosis: New aspects of immunopathogenesis. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6532002/
  5. Patsopoulos, N. A. (2018). Genetics of multiple sclerosis: An overview and new directions. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6027932/
  6. Smoking. (2019). https://mstrust.org.uk/a-z/smoking
  7. Study suggests Epstein-Barr virus may cause multiple sclerosis. (2022). https://www.nih.gov/news-events/nih-research-matters/study-suggests-epstein-barr-virus-may-cause-multiple-sclerosis
  8. What causes MS? (n.d.). https://www.nationalmssociety.org/What-is-MS/What-Causes-MS

Medical Reviewer: Sharon Stoll, DO, MS
Last Review Date: 2022 Aug 30
View All Finding the Right Multiple Sclerosis Treatment Articles
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.