Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

Multiple Sclerosis (MS)


The Manual's Editorial Staff

Reviewed/Revised Jan 2024
Get the full details
Topic Resources

What is multiple sclerosis (MS)?

Multiple sclerosis is a disease that causes multiple scars on nerves in your brain and spinal cord. These scars keep the nerves from working properly.

What Is Multiple Sclerosis?

What causes MS?

What are the symptoms of MS?

Because MS attacks different nerves, symptoms are different for different people. And the pattern of how symptoms come and go is different.

Usually, MS symptoms appear suddenly (called a flare) and then go away (called remission). Usually, you're in good health between flares. Most people have flares only every year or two, but you may have more. Each flare may affect a different part of your body. Flares can last a few days to a few months.

As time goes on, your symptoms may not go away completely between flares. In some people, symptoms never go away. Whatever your symptom pattern is, MS tends to slowly get worse.

Common early symptoms of MS include:

  • Tingling or numbness in parts of your arms, legs, chest, back, or face

  • Weakness, clumsiness, or stiffness in your arms or legs

  • Blind spots, blurry vision, or pain when moving one eye

Other early symptoms include:

  • Double vision (seeing two of one thing)

  • Sudden burning or electric shock-like pains down your back, legs, or arm that may come on their own, when something touches you, or when you bend your neck

Later symptoms of MS may include:

  • Shaky, irregular movements

  • Being unable to move a part or all of your body

  • Painful muscle cramps and muscle weakness

  • Balance and walking difficulty

  • Feeling tired and weak

  • Slow, slurred speech

  • Depression or mood swings

  • Difficulty thinking, remembering things, paying attention, or making decisions

  • Dizziness

  • Problems controlling urination (peeing) or bowel movements (pooping)

Symptoms may become worse if you're hot, such as on a hot day or during a fever.

How can doctors tell if I have MS?

How do doctors treat MS?

To treat symptom flares, doctors use:

  • Medicines called corticosteroids

If corticosteroids don't help, doctors may try a blood treatment called plasma exchange.

To help prevent flares of symptoms, doctors use various different medicines that help keep your immune system from attacking your nerves.

Doctors may use other medicines to treat specific symptoms, such as muscle tightness, tingling sensations, tiredness, and depression.

You can make life with MS easier and help prevent disability by:

Where can I find more information on MS?

Drugs Mentioned In This Article

Generic Name Select Brand Names
Calcidol, Calciferol, D3 Vitamin, DECARA, Deltalin, Dialyvite Vitamin D, Dialyvite Vitamin D3, Drisdol, D-Vita, Enfamil D-Vi-Sol, Ergo D, Fiber with Vitamin D3 Gummies Gluten-Free, Happy Sunshine Vitamin D3, MAXIMUM D3, PureMark Naturals Vitamin D, Replesta, Replesta Children's, Super Happy SUNSHINE Vitamin D3, Thera-D 2000, Thera-D 4000, Thera-D Rapid Repletion, THERA-D SPORT, UpSpring Baby Vitamin D, UpSpring Baby Vitamin D3, YumVs, YumVs Kids ZERO, YumVs ZERO
quiz link

Test your knowledge

Take a Quiz!