What is multiple sclerosis?

Multiple sclerosis (MS) is a lifelong condition that affects your brain and spinal cord. In MS, the coating that protects your nerves (myelin) is damaged. This damage disrupts how parts of the nervous system transmits signals.

This disruption causes a range of physical and mental signs and symptoms including how we think, move, see and feel. The symptoms and severity of MS are vary a lot from one person to another and change over time. This can sometimes make MS difficult to diagnose.

At the moment there is no known cure. There are however many different treatments and therapies available to help you manage MS’s progression and symptoms.

There are around 2.8 million people worldwide who have MS and it affects nearly three times as many women as men. People are generally diagnosed with MS between the ages of 20 and 50 although children and older adults develop it too.

Watch this explainer video from the Multiple Sclerosis Society (UK)

Different types of MS

There are four types of MS

Generally speaking there are four types of MS (although this is subject to some debate).

Clinically Isolated Syndrome (CIS)

Clinically Isolated Syndrome is the first episode of neurological symptoms caused by inflammation and demyelination in the nervous system (rather than by something like a fever or infection). The episode must last for longer than 24 hours and is characteristic of MS but does not necessarily mean you have MS.

For some people it can be a first sign of what turns out to be MS although for others it may be an isolated episode. It is possible to be diagnosed with MS from a CIS episode if an MRI shows previous damage to your brain or spinal cord at different points of time.

Find out more about CIS from the MS Trust

Relapsing remitting MS (RRMS)

RRMS is the most commonly diagnosed form of MS (around 85% of people). If you have RRMS you experience a period when symptoms flare up aggressively (sometimes referred to as a relapse, attack or exacerbation) followed by a period of partial or full recovery (often called remission).

It is difficult to predict when relapses might happen or how severe your symptoms might be. During periods of remission all symptoms may disappear or some symptoms may continue and become permanent. However, no new symptoms will appear and you will not get worse.

Disease modifying therapies (DMTs) are designed to treat RRMS and work to decrease the number and impact of your relapses.

Find out more about RRMS from the MS Trust

Secondary progressive MS (SPMS)

Over time if you are diagnosed with RRMS you may find that your MS changes. If you have fewer relapses but your disability increases, this is called secondary progressive MS.

You can be diagnosed with SPMS without being diagnosed with RRMS. This is being either your RRMS was not diagnosed because your previous relapses have been mild or gave no symptoms. It could also be that you have been diagnosed with something else previously and your diagnosis has been changed to MS.

Around half of people with RRMS go on to develop SPMS. Progression in MS is often not discussed so if you are concerned you should talk to your healthcare team about it.

Find out more about SPMS from the MS Trust

Primary progressive MS (PPMS)

PPMS is where your level of disability from MS increases from the start and you typically do not have any relapses. Around 10 - 15% of people with MS have PPMS. You can have periods of worsening symptoms which can look like relapses but this is still classified as PPMS.

Find out more about PPMS from the MS Trust

The many names of MS

MS is a complicated disease with lots of different terms and different doctors will sometimes use different names and change how they talk about it.

If you are not sure about anything that you are being told, please ask your doctor to explain it again or provide you some information to take home for you to read and understand in your own time.

Disease progression

Disease progression in MS is often not spoken about and can feel like a taboo subject that leaves you feeling afraid. Speaking to your healthcare team about it can help you understand it and feel better informed and more able to cope with your future with MS.


www.atlasofms.org. (n.d.). Number of people with MS | Atlas of MS. [online] Available at: https://www.atlasofms.org/map/global/epidemiology/number-of-people-with-ms.

‌MS Trust. (n.d.). Clinically isolated syndrome (CIS). [online] Available at: https://mstrust.org.uk/a-z/clinically-isolated-syndrome-cis.

‌MS Trust. (n.d.). Types of MS. [online] Available at: https://mstrust.org.uk/about-ms/what-ms/types-ms.

This article provides general information and discussions about health and related subjects. The information and other content provided in this blog, website or in any linked materials are not intended and should not be considered or used as a substitute for medical advice, diagnosis or treatment.