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Symptom changes over time

If you or your loved one has been diagnosed with Multiple Sclerosis (MS), you’ll likely think of it as a condition that sometimes flares up and then (hopefully) quietens. Because this is the form of MS with which people are most commonly diagnosed, it’s often (and very easily) thought of as a continual cycle which will keep following this pattern1. In fact, MS changes over time, with symptoms appearing in different ways2.

Each person’s MS is unique, and that isn’t just because of the types of symptoms that can appear, but also because there are three different types of MS.

The type of MS you have is usually determined by3,4:

  • Pattern of relapses (‘flare-ups’, ‘attacks’ or an ‘episode’ of MS symptoms that can last a few days, weeks, or even months)
  • Rate of  progression (the speed with which physical or cognitive tasks become more difficult over time. This also includes the accumulation of existing symptoms such as bowel, bladder and sexual dysfunction.)

Types of MS

Most people are diagnosed with RRMS, which is the flare-based phase of MS6. However, being initially diagnosed with RRMS doesn’t mean that your diagnosis won’t change over time, as it may move into the next phase of the disease. It’s easiest to think of MS as a spectrum which people often move along throughout their life, and many will, over time, transition to SPMS7.

This change from RRMS to SPMS means a gradual transition to symptoms that are potentially getting worse8. It may also mean increased disability, such as difficulty walking or fatigue-related problems9. SPMS is also associated with increased cognitive difficulties, such as short-term memory issues or difficulty concentrating10.

The third form of progressive MS is known as primary progressive MS (PPMS). This MS type is named like this because from the first (primary) symptom, it is progressive and symptoms slowly become worse over time.

    Progression Table RRMS

    In RRMS, periods when symptoms are more noticeable (relapses) are followed by periods of recovery (remission) when symptoms lessen or disappear.

    Progression Table SPMS

    In SPMS, relapses can become less frequent or even disappear. But symptoms that are getting worse – or new symptoms – may become more apparent as disability progresses.

    Progression Table PPMS

    In PPMS, symptoms (and disability) worsen from diagnosis without a relapsing phase in the early stages.

    The science behind the symptoms

    So, we now know that there are three different types of MS. But what’s actually happening inside the body? 11,12,13,14

    Your central nervous system includes your brain and spinal cord. It's made up of nerves that send signals all around your body. These signals control many things such as:   

    • Involuntary actions (e.g., breathing, heartbeat, senses)
    • Voluntary actions (e.g., moving, speaking)11

    MS is considered an autoimmune disease of the central nervous system. Lymphocytes (white blood cells in your immune system) mistake your myelin (coating around nerves) and axons (nerve fibers) for something that shouldn't be there12, 13.

    MS progression

    The lymphocytes then attack the healthy nerves, creating inflammation, which damages the myelin coating and exposes the axon nerve fibers12,13.

    Lymphocytes attacking health nerves
    Exposed Axon nerve fibres

    When your myelin is inflamed and damaged, you may experience a relapse—noticeable MS symptoms that last anywhere from a day to months12.

    Noticeable MS symptoms

    Over time with MS, there may be less myelin left to attack, and your axons, or nerve fibers, become more exposed. Picture your nerves as wires that have electrical signals trying to move through them, but no protective coating. Because of the lack of protective coating, your nerve signals, like electrical signals, can be slowed or stopped all together. Damage to your nerves builds up, which can potentially lead to more noticeable or more consistently present symptoms11,12.

    Nerve damage

    Spotting changes in symptoms

    Changes in the type and severity of MS symptoms you experience can happen over time, so this progression of the condition may not be that noticeable at first. Your symptoms may become more challenging and, while it might seem strange, you may even experience fewer relapses—not more. Experiencing fewer relapses but worsening symptoms can be a sign that your MS is progressing15. It’s important to look out for changes in symptoms because the kinds of treatment and support needed – both practical and emotional – might change too. By monitoring changes and communicating them to your MS specialist, neurologist or MS nurse, you can get ahead of MS progression, working with your healthcare professionals to find the right care for you.



    1. MS Trust. Relapsing remitting MS. Available at: Accessed May 2020.
    2. MS Society. Types of MS. Available at: Accessed April 2020.
    3. NHS.UK. Diagnosis. Available at: Accessed April 2020.
    4. MS trust. Types of MS. Available at: Accessed April 2020.
    5. National MS Society. Types of MS. Available at: Accessed June 2020.
    6. NHS.UK. Conditions. Available at: Accessed April 2020.
    7. Scalfari A, Neuhaus A, Daumer M, Muraro PA, Ebers GC. Onset of secondary progressive phase and long-term evolution of multiple sclerosis. J Neurol Neurosurg Psychiatry. 2014; 85: 67-75.
    8. National MS Society. Secondary Progressive MS. Available at: Accessed May 2020.
    9. MS Trust. What Are the Symptoms of Secondary-Progressive MS? Available at: Accessed April 2020.
    10. MS Society. Primary Progressive MS. Available at: Accessed April 2020.
    11. Menche N., Schmidt R., Lang F., Heckmann M. (2006) How does the nervous system work? (2006) Available at: Accessed April 2020.
    12. Dobson, R and Giavannoni, G. Multiple Sclerosis - a review (2018). pp. 27-40. Available at: Accessed June 2020.
    13. National MS Society. What causes MS. Available at: Accessed June 2020.
    14. MS Trust. MS: the facts. Available at: Accessed April 2020.
    15. MS Society. Secondary progressive MS. Available at: Accessed April 2020.

    UK | July 2020 | MUL20-C021