Multiple sclerosis (MS) is a disease of the nervous system. It causes swelling, harm, and scarring of the nerve sheath that covers the brain and spine. There can also be harm to the nerve itself.

Nerve cells (neurons) showing normal and damaged myelin sheaths
nucleus image

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There are many types:

  • Relapsing-remitting—Problems return for few months or years, last for a few weeks or months, and then go away. They may get worse each time.
  • Primary progressive—Problems slowly worsen after they first show up. They don't go away and come back.
  • Secondary progressive—After years of going away and coming back, problems start to get worse.
  • Progressive relapsing—Problems slowly worsen after they first happen. One or more relapses may also happen.

Multiple Sclerosis

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A problem with the body's immune system seems to be the cause. It is not known why this happens. The system protects the body from infection and disease. With MS, it starts attacking the body instead. These health problems may lead to MS:

  • Viral or other infection
  • Your genes
  • Environmental causes

Frohman EM, Goodin DS, et al. The utility of MRI in suspected MS: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology. 2003 Sep 9;61(5):602-611.

Khan O, Williams MJ, Amezcua L, Javed A, Larsen KE, Smrtka JM. Multiple sclerosis in US minority populations: Clinical practice insights. Neurol Clin Pract. 2015;5(2):132-142.

Multiple sclerosis (MS). EBSCO DynaMed Plus website. Available at: Updated July 23, 2018. Accessed September 26, 2018.

NINDS multiple sclerosis information page. National Institute of Neurological Disorders and Stroke website. Available at: Accessed September 27, 2018.

What is MS? National Multiple Sclerosis Society website. Available at: Accessed September 26, 2018.

Last reviewed September 2018 by EBSCO Medical Review Board Rimas Lukas, MD  Last Updated 9/26/2018