• Consumer Health: Are you at risk for MS?

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MS Awareness Week will be observed March 12–19, which makes this a good time to learn about who might be at risk of developing this potentially disabling disease of the brain and spinal cord.

Multiple sclerosis, or MS, affects nearly 1 million people living in the U.S., according to the National Multiple Sclerosis Society. With MS, the immune system attacks the protective sheath that covers nerve fibers, and causes communication problems between your brain and the rest of your body. Eventually, the disease can cause the nerves to deteriorate or become permanently damaged.

Signs and symptoms of MS can differ greatly from person to person and over the course of the disease, depending on the location of affected nerve fibers. Some people with severe MS may lose the ability to walk independently or at all, while others may experience long periods of remission without any new symptoms.

Most people with MS have a relapsing-remitting disease course. This means that they experience periods of new symptoms or relapses that develop over days or weeks, and usually improve partially or completely. These relapses are followed by quiet periods of disease remission that can last months or even years.

Risk factors

The cause of multiple sclerosis is unknown, but these factors may increase your risk:

  • Age
    MS can occur at any age, but onset usually occurs around 20–40.
  • Sex
    Women are more than two to three times as likely as men to have relapsing-remitting MS.
  • Family history
    If one of your parents or siblings has had MS, you are at higher risk of developing the disease.
  • Certain infections
    A variety of viruses have been linked to MS, including Epstein-Barr, the virus that causes infectious mononucleosis.
  • Race
    White people, particularly those of Northern European descent, are at highest risk of developing MS. People of Asian, African or Native American descent have the lowest risk.
  • Climate
    MS is far more common in countries with temperate climates, including Canada, the northern U.S., New Zealand, southeastern Australia and Europe. Your birth month also may affect the chances of developing MS, since exposure to the sun when a mother is pregnant seems to decrease later development of multiple sclerosis in these children.
  • Vitamin D
    Having low levels of vitamin D and low exposure to sunlight is associated with a greater risk of MS.
  • Genetics
    A gene on chromosome 6p21 has been found to be associated with MS.
  • Obesity
    An association between obesity and MS has been found in females. This is especially true for female childhood and adolescent obesity.
  • Certain autoimmune diseases
    You have a slightly higher risk of developing MS if you have other autoimmune disorders such as thyroid disease, pernicious anemia, psoriasis, Type 1 diabetes or inflammatory bowel disease.
  • Smoking
    Smokers who experience an initial symptom that may signal MS are more likely than nonsmokers to develop a second event that confirms relapsing-remitting MS.

Connect with others talking about MS in the Multiple Sclerosis (MS) support group on Mayo Clinic Connect, an online patient community moderated by Mayo Clinic.

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