Risk Factors for Multiple Sclerosis (MS)

A risk factor raises your chance of getting a health problem.

You can get MS with or without the risk factors below. But the more risk factors you have, the greater your chances of getting it. If you have many, ask your doctor what you can do to lower your risk.

Risk factors are:

Medical Problems

A viral infection may trigger MS. Researchers have been looking into a type of herpes virus, human herpes virus-6, and Epstein-Barr virus. Some believe that it is the way some people respond to the virus that may trigger MS.

People who have had optic neuritis (swelling of the optic nerve) have a high risk.


People between 16 and 40 are at higher risk. This is when MS is found in most people.


MS is found in women at younger ages than men. MS is found in men and women at equal rates later in life.


MS may be due to your genes because it happens in families. Researchers think more than one gene is to blame.

People with a family history of problems with their immune system, such as systemic lupus erythematosus, are also at greater risk.

Ethnic Background

MS is more common in people of European descent.

Vitamin D

Some studies have found that people with lowvitamin D levels had a greater risk of MS. But researchers are still looking into this.

If you are worried about your vitamin D level, talk to your doctor. Your blood can be tested. Vitamin D can be found in foods like cod liver oil, salmon, mackerel, sardines, and milk that contains it. You can also get it from the sun. It triggers your body to make it.

Other Factors

Smokingis thought to be linked to a higher risk.



Ebers GC. Environmental factors and MS. Lancet Neurology. 2008;7(3):268-277.
Goodin DS, Frohman EM, et al. Disease modifying therapies in multiple sclerosis: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology and the MS Council for Clinical Practice Guidelines. Neurology. 2002 Jan 22;58(2):169-178.
Multiple sclerosis (MS). EBSCO DynaMed Plus website. Available at: http://www.dynamed.... Updated July 23, 2018. Accessed September 26, 2018.
NINDS multiple sclerosis information page. National Institute of Neurological Disorders and Stroke website. Available at: https://www.ninds.nih.gov/Disorders/All-Disorders/Multiple-Sclerosis-Information-Page. Accessed September 27, 2018.
Nolan D, Castley A, Tschochner M, et al. Contributions of vitamin D response elements and HLA promoters to multiple sclerosis risk. Neurology. 2012;79(6):538-546.
What is MS? National Multiple Sclerosis Society website. Available at:
...(Click grey area to select URL)
Accessed September 13, 2016.
11/9/2015 DynaMed Plus Systematic Literature Surveillance http://www.dynamed...: Kuo CF, Grainge MJ, Valdes AM, et al. Familial aggregation of systemic lupus erythematosus and coaggregation of autoimmune diseases in affected families. JAMA Intern Med. 2015;175(9):1518-1526.
Last reviewed September 2018 by EBSCO Medical Review Board Rimas Lukas, MD
Last Updated 9/26/2018

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