Comparison of Fibromyalgia and MS

Similar Symptoms But Unique Diagnosis

Headaches are a symptom of both fibromyalgia and MS.
Headaches are a symptom of both fibromyalgia and MS. elenaleonova/Getty Images

MS and fibromyalgia share many symptoms. For instance, depression is a common symptom in both conditions and may be a result of the disease process itself, a consequence of having such a debilitating disease, or a little bit of both. Other common symptoms include:

  • fatigue
  • pain
  • sleep disturbances
  • headaches and migraines
  • bladder and bowel problems
  • negative impact on quality of life and ability to perform everyday activities (disability)

    This overlap in symptoms may confuse a diagnosis of fibromyalgia and multiple sclerosis, especially in someone already living with one of these conditions. It's plausible that doctors, and people living with the disease themselves, would naturally assume that the symptoms were part of the original diagnosis and be hesitant to investigate further.

    Who Gets Fibromyalgia and/or Multiple Sclerosis?

    Fibromyalgia is much more common than MS, as it's estimated that one in 50 (or over 6 million) people in the U.S. have fibromyalgia. In contrast, MS affects less than 10 percent of that number, or a roughly estimated 400,000 people in the US. That said, there are some commonalities in who is affected:

    Women: Between 80 and 90 percent of people with fibromyalgia are female. Women are more likely to have MS (relapsing-remitting MS), too, but only 2 or 3 times more likely than men.

    Young at Diagnosis: Most people with fibromyalgia are diagnosed when they are between 20 and 55 years old.

    Similarly, most people with MS are diagnosed when they are between 20 and 50 years old.

    Diagnosis of Fibromyalgia and Multiple Sclerosis

    While there are no blood tests to definitively diagnose either fibromyalgia or multiple sclerosis, there are specific criteria used by doctors -- this greatly helps prevent a misdiagnosis.

    Still, it can be challenging in some people, as clinical symptoms can overlap.

    Fibromyalgia is diagnosed when a person meets one of the two criteria:

    • A Widespread Pain Index Score that is 7 or greater and Symptom Severity Scale Score that is 5 or greater OR
    • A Widespread Pain Index Score that is 3 to 6 and a Symptom Severity Scale Score that is 9 or greater.

    Widespread pain index (WPI) ranges in score from 0 to 19 and is based on the number of sites that a person reports pain over the past week. For example, pain in the right lower leg, left lower leg, abdomen, left hip, and left jaw would be a score of 5.

    The Symptom Severity (SS) scale score is the sum of severity scores (ranging from 0 to 3) of the following four symptoms: fatigue, waking unrefreshed, cognitive symptoms, and extent of general somatic ("body") symptoms for a total score of 0 to 12.

    Diagnosis of multiple sclerosis relies heavily on the presence of lesions on the brain or spinal cord, as seen on an MRI scan. MS can also be diagnosed clinically -- meaning a person has symptoms that occur at different periods of time (at least one month apart) and within different parts of the brain, spinal cord, or optic nerve ( at least 2 different areas).

    Bottom Line

    Given the overlap in many of the symptoms of these diseases, as well as the similar risk profiles and diagnostic challenges, it's plausible there are people who have both MS and fibromyalgia, or that one is mistaken for the other. If you are concerned about this, it's sensible to ask for a referral to a rheumatologist (or a neurologist for MS symptoms) to get additional information and a second opinion.

    That being said, it's important to understand that having one condition does not put you at risk for having the other -- meaning if you have been diagnosed with fibromyalgia, it does not mean you have a higher chance of developing MS (and vice versa).

    There is no cure for either disease, but there are medications to treat many of the symptoms, as well as to keep MS from progressing. It's worth your time and effort to keep asking questions and keep seeking improved health and a better quality of life.


    National MS Society. Diagnosing MS.

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    Tullman, M.J. (2013). Overview of the epidemiology, diagnosis, and disease progression associated with multiple sclerosis. American Journal of Managed Care, Feb;19(2 Suppl):S15-20.

    Weir, P.T., Harlan, G.A., Nkoy, F.L., Jones, S.S., Hegmann, K.T., Gren, L.H., & Lyon, J.L. (2006). The incidence of fibromyalgia and its associated comorbidities: a population-based retrospective cohort study based on International Classification of Diseases, 9th Revision codes. J Clin Rheumatol. 2006 Jun;12(3):124-8.

    DISCLAIMER: The information in this site is for educational purposes only. It should not be used as a substitute for personal care by a licensed physician. Please see your doctor for diagnosis and treatment of any concerning symptoms or medical condition.

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