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Relapsing remitting MS (RRMS)

In relapsing remitting MS (RRMS) people have attacks of new and old symptoms, this is called a relapse. Around 85% of people with multiple sclerosis are diagnosed with RRMS. Taking a disease modifying therapy (DMT) could mean fewer relapses and slow down your MS.

The relapsing remitting label can help to explain MS to others and help you to find the best treatments. But it can't predict exactly how MS will affect you.

For most people with MS, this is the way their MS begins, except for the small group of people who have primary progressive MS (about 15% of all people with MS).

Your questions about relapsing remitting MS (RRMS)

What is a relapse?

A relapse is defined by "the appearance of new symptoms, or the return of old symptoms, for a period of 24 hours or more – in the absence of a change in core body temperature or infection". Symptoms you have experienced before, or perhaps grown used to dealing with, might appear in a different part of the body.

In relapses, symptoms usually come on over a short period of time – over hours or days. They often stay for a number of weeks, usually four to six, though this can vary from very short periods of only a few days to many months.

Relapses can vary from mild to severe. At their worst, acute relapses may need hospital treatment, but many relapses are managed at home, with the support of the GP, MS specialist nurse, and other care professionals.

Symptoms which come and go can sometimes be considered a relapse – they don’t always have to be continuous. For example, some people experience a shock-like sensation when they bend their neck. This can be considered a relapse if it occurs every time they bend their neck for at least 24 hours.

Medical staff might call relapses things like attack, flare-up, exacerbation, acute episode or clinical event.

Will I recover completely from a relapse?

People often make a very good recovery from a relapse, with complete remission. However, this is not always the case and around half of all relapses may leave some lingering problems, however slight.

This is because, if the damage to myelin is severe, then some symptoms remain, though they may still improve over the following months.

Our understanding of how MS attacks the body is changing. MS specialists used to think that once a relapse was over the attack, the damage to your brain and spinal cord stops and no new damage was happening. But now we know that even when you aren't having relapses MS can still be causing damage.

This damage can be happening even if there are no signs of it that you might notice, such as a relapse. That's why treatment with a disease modifying therapy (DMT) should be offered to you as close to when you're diagnosed as possible.

What brings on or prevents relapses?

Many people with MS feel they can identify things that trigger a relapse for them. Unfortunately, what appears to affect one person doesn’t always apply to someone else, and research has not yet found what triggers a relapse. This makes it hard to give definite strategies for reducing the risk of relapses. But there is one thing we know that can reduce the number of relapses people get: treatment with a disease modifying therapy (DMT).

Disease modifying therapies

Disease modifying therapies (DMTs) are used to treat types of MS where you get relapses. They can reduce how many relapses you get and can slow down the rate at which disability happens to you. But they can't undo any permanent disability that you already have.

To reduce the risk of permanent damage to your body, you should be offered a DMT as soon as possible after a diagnosis of relapsing MS. DMTs work better the sooner you start them but taking one later can still have benefits.

These drugs can have side effects, some serious, but not being treated means the risk of more relapses and more long-term disability.

> Find out more about DMTs


Over the years, many studies have looked at whether there is a link between psychological stress and MS getting worse. The evidence is not absolutely clear, but many experts believe that stress might be one of many factors which could increase the risk of a relapse. Anecdotally, many people affected by MS cite stress as a major factor in bringing on a relapse.


Some infections, for example a bladder infection, may also make an attack more likely. For this reason, people with MS are encouraged to treat bacterial infections early.


There’s no proven link between vaccinations (eg. for flu, hepatitis B or any travel vaccines) and a relapse. If you're going to an area where a serious infectious disease is prevalent, it's generally far better to have a vaccination than to risk serious illness, which could have far worse consequences.


There is an increased risk of a relapse in the months immediately after giving birth (though many women with MS find that they have fewer relapses during pregnancy).

> Find out more about pregnancy and MS

What isn't a relapse?

It’s often difficult, especially in the first few years, to know what is and what isn’t a relapse. It's not uncommon to experience some ‘on-off’ symptoms even during remission – for example, fatigue or balance problems.

New symptoms can be shocking or distressing at any time, but not every symptom will be a sign that a relapse is beginning. Over time, you will get more confident in understanding the symptoms as you get to know your MS.

Don’t put everything down to MS. This can stops you exploring everything that could be causing a new symptom. It's possible that it's nothing to do with MS and needs to be checked out.

Managing relapsing remitting MS (RRMS)

Managing symptoms

There are treatments and ways of managing symptoms which can help manage many different MS symptoms.

> Find out more about managing symptoms

Managing relapses

> Find out about strategies and treatments for managing relapses

Disease modifying therapies

Disease modifying therapies (DMTs) can reduce the number of relapses you get and slow down the rate at which disability happens to you. They work better the earlier you start taking them. Damage caused by MS builds up over time, so the sooner you begin treatment, the less damage will have built up before treatment starts to take effect.

Official guidelines recommend that everyone with MS has a review with their specialist at least once a year. You should be deciding together with your specialist what your treatment plan is. Treatment with a DMT can keep your number of relapses as low as possible and slow down the damage building up that can lead to permanent disability.

> Find out more about DMTs