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Multiple Sclerosis

Medically reviewed by: Gurcharanjeet Kaur, MD

What Is Multiple Sclerosis?

Multiple sclerosis, or MS, is a disease that affects the central nervous system. In MS, roadblocks in nerve pathways prevent messages from reaching the brain as they should.

The symptoms of MS vary depending on which nerves are affected. The disease does tend to get slowly worse over time. But most people with MS have mild symptoms, which can be helped with medicines and other treatments.

What Happens With Multiple Sclerosis?

A layer of tissue called myelin (MYE-uh-len) surrounds and protects the nerves. In multiple sclerosis (skleh-ROE-sis), the immune system, which usually fights germs, attacks myelin in the brain, spinal cord, and optic nerve. This leads to scarring that slows down or blocks the signals that travel between the brain and the body. This damage to the nerves and surrounding tissue leads to symptoms such as vision problems or a person feeling unsteady on their feet.

What Causes Multiple Sclerosis?

Experts don’t know what exactly triggers MS. It’s thought to be partly genetic, but other things might play a role, such as low levels of vitamin D, childhood obesity, geographic location, and smoking.

What Are the Signs & Symptoms of Multiple Sclerosis?

Multiple sclerosis symptoms come and go in episodes or attacks. They can include:

  • vision problems
  • tiredness or weakness
  • difficulty walking or trouble with balance or coordination
  • slurred speech
  • numbness or a pins-and-needles tingling
  • memory problems

These problems can last for a few days or several months. In some people with MS, they can become increasingly debilitating with no periods of remission.

What Are the Types of Multiple Sclerosis?

There are four categories of MS:

  • Clinically isolated syndrome: This is the first attack of a disease that might be MS, but there’s no diagnosis yet. It can cause problems in the nerve of the eye (called optic neuritis), problems with the brainstem, or problems with the spinal cord (transverse myelitis).
  • Relapsing-remitting: In this most common form of MS, symptoms come and go. People with this type will have symptoms during relapses (also called exacerbations). The problems will lessen (remit) or stop between relapses.
  • Primary-progressive: People with this kind of MS have constant symptoms, which tend to get worse over time.
  • Secondary-progressive: People with secondary-progressive start out with a period of relapsing-remitting symptoms before symptoms gradually get worse. Without treatment, most people in the relapsing-remitting category will develop this form of MS within 10 years.

How Is Multiple Sclerosis Diagnosed?

Most people with MS are diagnosed when they're 20–50 years old. The disease is more common in women than men. MS is rare in kids. It also tends to progress more slowly in kids than in adults.

When people begin to have what could be early signs of MS, such as vision or balance problems, doctors will take a careful medical history and do an exam. No single test can find out if a person has MS. So doctors order tests such as:

  • blood tests, to rule out other conditions that cause similar symptoms
  • a spinal tap, to get a sample of cerebrospinal fluid (the fluid that surrounds the brain and spinal cord) to test for antibodies and proteins
  • a brain MRI, to check for signs of scars in the brain and spinal cord
  • evoked potentials (EP) tests, which test the time it takes for nerves to respond. A slow response time could mean there's damage along the nerve pathways.

How Is Multiple Sclerosis Treated?

There is no known cure for multiple sclerosis, but medicines can help control symptoms, reduce the number of relapses, and slow down the progression of the disease.

Steroids, for instance, given during a relapse can ease inflammation and help someone recover.

Disease-Modifying Therapies

Disease-modifying therapies (DMTs) are medicines used for people who have relapsing types of MS. Researchers hope that new DMTs might someday work against progressive types of MS too.

DMTs work best when they start as soon as possible after diagnosis. That’s because the damage MS causes builds over time.

Some DMTs are given as injections (shots) that can be done at home. Some are taken by mouth, and some are given as an IV infusion (or “drip”) at a hospital or clinic. These treatments:

  • prevent relapses 
  • prevent new scarring (or lesions) in the brain and spinal cord
  • slow the damage that leads to disabilities
  • may help prevent permanent nervous system damage

DMTs (sometimes called disease-modifying drugs, or DMDs) do not help manage MS symptoms such as dizziness, eye problems, or muscle weakness. Some DMTs can cause serious side effects, so the care team closely monitors the treatments.

What Else Should I Know?

Physical therapy, speech-language therapy, and occupational therapy can help people with MS manage symptoms. Eating a balanced diet and exercising regularly also contribute to overall health and well-being for those living with MS.

You also can find support and more information online at:

Medically reviewed by: Gurcharanjeet Kaur, MD
Date reviewed: March 2020