MRI scan showing MS lesions in the brain
1 / 11

What Happens During a Relapse?

When you experience a multiple sclerosis relapse (also known as an exacerbation or flare-up), it's because new damage in the brain or spinal cord disrupts nerve signals. That's why you might notice new symptoms or the return of old symptoms. A true relapse lasts more than 24 hours and happens at least 30 days after any previous relapses. Relapses vary in length, severity, and symptoms. Over time, symptoms should improve. Many people recover from their relapses without treatment.

Swipe to advance
Woman dropping a bag of groceries in her driveway
2 / 11


Damage to the protective covering of nerve fibers interrupts normal signals from the brain to the body. When those signals are disrupted, your body doesn't function like it once did. Things you did easily before can seem difficult -- like opening a jar or turning a doorknob. Sudden or worsening weakness that doesn't go away could mean you're having a relapse.

Swipe to advance
Woman having trouble reading labels in store
3 / 11

Vision Problems

If your vision is blurred or you're seeing double, you could be starting to relapse. Some people also lose their depth or color perception as the optic nerve becomes inflamed. Taking a hot shower or bath or having a viral infection like the flu can sometimes trigger vision problems, but these are only temporary and should go away within a day.

Swipe to advance
Woman having trouble clasping a necklace
4 / 11

Numbness or Tingling

Numbness is one of the most common signs of a multiple sclerosis relapse. You can lose so much feeling that it's hard to use your hands or other affected body parts. You might not be able to write or hold a coffee cup. If numbness is new or getting worse, it's time to call your doctor.

Swipe to advance
Woman confused while reading
5 / 11

Thought Problems

It's frustrating to forget where you left your car keys, or to have to re-read the same paragraph over and over just to understand it. MS can affect your mind in many ways, interfering with memory, concentration, language, and information processing, especially as the disease progresses. Any new trouble thinking clearly or remembering past events is a warning that you could be in the midst of a relapse.

Swipe to advance
Woman experiencing extreme dizziness
6 / 11


Feeling lightheaded or unsteady on your feet can be an unsettling experience, but it's a common sign of MS relapses. The dizziness is due to damage in the parts of your brain that control equilibrium. A motion sickness drug can take away that 'room-is-spinning' feeling in the short term, but if it lasts more than a day you may need to be treated for an exacerbation.

Swipe to advance
Woman losing balance and falling on stairs
7 / 11

Balance and Coordination

"Somebody may start to feel like they're drunk when they walk, or they [may] have trouble coordinating movements in their arm," says John Ratchford, MD, MSc, assistant professor of neurology at the Johns Hopkins University School of Medicine. Muscle weakness or spasm, numbness, and a loss of balance during a relapse can make you uncoordinated and unsteady on your feet.

Swipe to advance
Man dripping with sweat indoors
8 / 11

Does Heat Trigger Relapses?

Soak in a hot tub or sit outside on a muggy day and you might feel like you're having a flare-up -- but you're not. "There's a lot of confusion among patients about heat," says Aaron Miller, MD, medical director of the Corinne Goldsmith Dickinson Center for Multiple Sclerosis at the Mount Sinai School of Medicine. Heat may bring on MS symptoms, but they'll go away as soon as you cool off.

Swipe to advance
African American woman sick and in bed
9 / 11

What Causes a Relapse?

A recent bout of the flu or other infection can trigger an MS relapse, some studies have suggested. Other suspected triggers are less certain, including stress, which is hard to study because it affects everyone differently. "I think it's quite possible that for some people, stress can have effects on the immune system and potentially increase the risk for a relapse," Ratchford says.

Swipe to advance
Healthcare worker helping with woman with meds
10 / 11

Preventing Relapses

The best way to prevent relapses is to take the medicine your doctor prescribes. "All of the medicines we use for relapsing MS have been shown to reduce the frequency of relapses -- that's the main reason they were approved," Miller says. Eating well, sleeping enough, and reducing stress are also good advice. Call your doctor if any new symptom appears or gets worse, and doesn't go away after 24 hours.

Swipe to advance
Man receiving infusion therapy
11 / 11

Treating Relapses

Not every relapse needs to be treated. If movement isn't limited and you're not uncomfortable, your doctor might recommend waiting until the symptoms improve on their own. For more bothersome exacerbations, intravenous steroids can speed recovery. Sometimes plasma exchange -- removing the blood and replacing the liquid part -- is used to treat more severe relapses.

Swipe to advance

Up Next

Next Slideshow Title

Sources | Medically Reviewed on 05/27/2020 Reviewed by Gabriela Pichardo on May 27, 2020


(1)    © 2011 Photo Researchers, Inc. All Rights Reserved.
(2)    Jasper James / Taxi
(3)    Keith Brofsky / UpperCut Images
(4)    Jodi Jacobson / Photodisc
(5)    Blend Images / Hill Street Studios
(6)    Hitoshi Nishimura / Taxi Japan
(7)    MIXA
(8)    Thinkstock / Comstock Images
(9)    Image Source
(10)    Yellow Dog Productions / Lifesize
(11)    Xavier Bonghi / Stone


John Ratchford, MD, MSc, assistant professor of neurology, Johns Hopkins University School of Medicine.
Aaron Miller, MD, medical director, Corinne Goldsmith Dickinson Center for Multiple Sclerosis, Mount Sinai School of Medicine; chief medical officer, National Multiple Sclerosis Society.
National MS Society: "For People with Relapsing MS," "Exacerbations," "Vision Problems," "Numbness," "Cognitive Function," "Dizziness and Vertigo," "Walking (Gait), Balance, and Coordination Problems," "Heat and Temperature Sensitivity."
Cedars-Sinai Medical Center: "Multiple Sclerosis (MS)."
Oikonen, M., et al. Multiple Sclerosis Journal, January 6, 2011 [Epub ahead of print].
Artemiadis, A. Neuroepidemiology, February 2011; vol. 36: pp 109-120.
Mohr, D. BMJ, March 2004; vol. 328: pp 731.

Reviewed by Gabriela Pichardo on May 27, 2020

This tool does not provide medical advice. See additional information.

THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional medical advice, diagnosis or treatment and should not be relied on to make decisions about your health. Never ignore professional medical advice in seeking treatment because of something you have read on the WebMD Site. If you think you may have a medical emergency, immediately call your doctor or dial 911.