Multiple sclerosis (MS) is an autoimmune disease in which the immune system attacks and destroys the protective covering of nerve cells (myelin) of the brain, spinal cord, and/or eyes. This impairs nerve signaling and causes a wide variety of potential symptoms, such as muscle weakness, pain, and problems with thinking and memory. The precise cause of MS is unknown.

Frequently Asked Questions

  • What causes multiple sclerosis?

    Multiple sclerosis symptoms are caused by your immune system mistakenly destroying the myelin sheath on the nerves, which impairs their function. Researchers are still trying to determine what leads to the autoimmune reaction, but sound theories include infectious disease, vitamin D levels, and a combination of genetics and environmental factors.

  • Is multiple sclerosis genetic?

    Experts suspect that certain genetic combinations increase your risk of developing multiple sclerosis. They’ve identified several genes that appear to be linked to the disease. If you have a parent or sibling who has it, you’re more likely to develop it. However, it’s far from guaranteed—a parent raises your risk from 0.13 to 2% and a sibling raises it to 5%.

  • Is multiple sclerosis fatal?

    Multiple sclerosis is rarely fatal. Some people with this disease may have a lifespan that’s slightly shorter than average, but it’s increased over time due to better treatments. Most people with multiple sclerosis live long lives and die of unrelated causes, like heart disease or cancer.

  • How is multiple sclerosis diagnosed?

    Multiple sclerosis is diagnosed using a variety of tests, including:

    • Neurological exam
    • Evoked potential test (to evaluate nerve response)
    • MRI of the brain and/or spinal cord
    • Spinal tap (lumbar puncture)
    • Tests to rule out other potential causes of symptoms

    Diagnosing this disease can be difficult. Symptoms can be subtle and many are shared by other medical conditions.

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  1. Johns Hopkins Medicine. Disorders of the Immune System.