What Is MS?

Reviewed by: HU Medical Review Board | Last reviewed: January 2022 | Last updated: January 2022

Multiple sclerosis (MS) is an illness of the central nervous system (CNS). This system includes the brain, spinal cord, and optic nerves. The CNS sends and receives nerve messages internally, as well as to and from nerves throughout the rest of the body. These nerve signals help you move your limbs, use your senses like sight and touch, and even think.1

MS is an autoimmune disease, meaning your immune system attacks your body rather than protecting it. With MS, the immune system attacks CNS myelin, a covering that protects your nerve fibers. This leads to communication issues between the brain and body, along with permanent nerve damage.1,2

Types of MS

There are 4 types of multiple sclerosis:1,3

  • Relapsing-remitting MS (RRMS) – 85 percent of people with MS are initially diagnosed with this form of the disease. It is defined by discrete episodes of new neurologic symptoms, called relapses, attacks, or flare-ups. These relapses are a result of new inflammatory lesions within the CNS. This is followed by periods with few or no symptoms, known as remission. Periods of remission can last months or years.
  • Secondary progressive MS (SPMS) – SPMS starts as relapsing-remitting, then evolves to secondary progressive. This means disability gets worse gradually over time, even without discrete attacks or new lesions.
  • Primary progressive MS (PPMS) – With PPMS, disability gradually gets worse from the start, and you will not have relapses or remissions. Around 15 percent of people with MS have this form of the disease.
  • Clinically Isolated Syndrome (CIS) – CIS is a diagnosis related to MS. CIS is when a person has only had 1 clinical attack of neurologic symptoms but does not currently meet diagnostic criteria for MS. You may develop MS in the future, but it is not guaranteed. Your doctor may suggest treatments that hold MS in check for a while.

Who gets MS?

Multiple sclerosis is not directly passed from one person to another, either through bodily contact or your genes. However, scientists have identified people who are at higher risk of getting the illness:2,4

  • Young to middle-aged adults – Doctors diagnose most people with MS between the ages of 20 and 50. However, children and older adults can get the disease, too.
  • People living in temperate climates – You are more likely to have MS if you live in Canada, the United States, New Zealand, southeastern Australia, and Europe. These countries are all far from the equator.
  • Women – Women are 2 to 3 times more likely to develop MS than men. Experts think hormones may be a factor.
  • White people – Anyone can develop MS, but white people with a northern European background are most affected. Recent research shows that Black women may have a higher risk than once thought.
  • People with a family history of MS – You are more likely to get MS if a parent or sibling also has the disease.
  • People with certain infections – Researchers have connected several viruses to MS.
  • Smokers – If you are a smoker and have early signs of MS, you are more likely to have another round of symptoms than those who do not smoke.
  • People with low vitamin D levels – Scientists have linked a lack of vitamin D to a higher chance of developing MS.
  • People with certain autoimmune diseases – Your odds of developing MS slightly increase if you have: thyroid disease, pernicious anemia, psoriasis, type 1 diabetes, inflammatory bowel disease (IBD), a family history of autoimmune diseases.

What causes MS?

Right now, we do not know what causes multiple sclerosis. Scientists are looking into different possible explanations, including:5

  • Our immune system
  • Disease patterns across large groups
  • Genes
  • Viruses and other infections

What are the symptoms of MS?

Symptoms of MS depend on which areas of the CNS are affected and which form of the disease you have. It can cause problems with:2

  • Movement, including limb weakness,tremor, and unstable walk
  • Sensory, including limb or face numbness, tingling, electric-shock sensations, and squeezing sensations around the abdomen or chest
  • Vision, including loss of vision, double vision, and blurred vision
  • Slurred speech
  • Extreme tiredness (fatigue)
  • Pain, including muscle stiffness (spasticity)
  • Sexual, bowel, and bladder dysfunction
  • Cognitive or memory issues

How is MS diagnosed?

No one test can diagnose MS. You may need to take several tests to rule out other illnesses. After sharing your medical history and undergoing an exam, your doctor may suggest:2

  • Blood tests – Other illnesses may mimic the signs and symptoms of MS. Blood tests help doctors to rule them out.
  • Spinal tap – Doctors draw out a small amount of fluid from your spinal canal for testing. They are looking for changes to antibodies linked to MS and to rule out other illnesses.
  • MRI – This test can show whether you have lesions on your brain and spinal cord consistent with MS.
  • Evoked potential tests - Your nervous system makes electrical signals in response to stimuli. A visual evoked potential test records these signals as you watch a moving visual pattern. Another type of test involves applying electrical impulses to your limbs. Doctors then measure the speed at which information moves down your nerve pathways.

How is MS treated?

There are 3 goals in treating MS: managing relapses, slowing the disease, and controlling symptoms. Here are some common MS therapies:1,2,4

Managing relapses

  • Corticosteroids (steroids)
  • Plasma exchange (plasmapheresis)

Slowing disease

  • Injectable drugs
  • Oral drugs
  • Infusion drugs

Controlling symptoms

  • Physical therapy
  • Muscle relaxants
  • Drugs to ease tiredness
  • Drugs to build walking speed
  • Other drugs for depression, pain, sexual problems, insomnia, and bladder or bowel control issues

What is the outcome for MS?

Right now, multiple sclerosis does not have a cure. But you can manage it with medicine and lifestyle changes like getting enough sleep, exercising, and reducing stress. Keep in mind that some people with MS have mild symptoms and do not need treatment.2

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