How to Recognize an MS Attack

Medically Reviewed by Christopher Melinosky, MD on June 07, 2021

Most forms of multiple sclerosis (MS) involve stretches of time when you feel good and other times when your symptoms act up. You might hear those worse periods called:

  • Attacks
  • Relapses
  • Flare-ups
  • Episodes
  • Exacerbations

How do you know if what you’re having is one?

Signs of an MS Attack

During an attack, some symptoms you’ve had may get worse, or you could have new ones.

These can include:

  • Fatigue
  • Dizziness
  • Problems with balance and coordination
  • Trouble with your vision
  • Issues with your bladder
  • Numb or tingling feelings (pins and needles)
  • Problems with your memory
  • Trouble concentrating

It's a relapse if:

  • You hadn’t had symptoms for at least 30 days before the ones you’re having now started. Otherwise, your symptoms are still part of the earlier flare-up.
  • They last at least 24 hours. But don’t wait to call your doctor if your symptoms are very serious, even if it hasn’t been a day. (For example: You’re so weak, you can’t move.) 
  • There’s no obvious trigger, like getting overheated.

Not all symptoms are signs of a relapse. If yours last less than 48 hours, you may have had something called a pseudoexacerbation. That’s when you temporarily feel symptoms. This is is usually caused by a systemic infection or stress and does not cause new brain lesions

Keep in mind that if you have even the slightest fever, it could be a sign of an infection. That also can cause problems like those you’d feel in a relapse.

What to Do

If you think you’re having a relapse, call your MS doctor right away, even if you don’t think it’s major. They’ll ask about your symptoms, how long you’ve had them, if you’ve been sick, and if you’ve changed any of your medication.

A relapse doesn’t necessarily need treatment. In some cases, symptoms will ease on their own. Still, the fact you’re having one can help your doctor decide how you may be treated moving forward.

Every person is different, so it may be hard to track down what can trigger a relapse for you. As you get more familiar with how the condition affects you, you’ll recognize your symptoms more easily and know what to do about them.

Show Sources


Multiple Sclerosis Association of America: “What Is An MS Relapse?”

Multiple Sclerosis Trust: “Relapse.”

National Multiple Sclerosis Society: “What Is MS?” "Heat & Temperature Sensitivity," "Managing Relapses."

Fiona Gupta, MD, neurologist, Hackensack University Medical Center, New Jersey.

Multiple Sclerosis Society U.K.: "Relapsing Remitting Multiple Sclerosis (RRMS)."

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