How Does Multiple Sclerosis Affect the Body?


Published: 14 April 2021

Multiple sclerosis is the most prevalent chronic progressive neurological disease among young people, affecting over 25 600 Australians in total (MS QLD 2019).

What Is Multiple Sclerosis?

multiple sclerosis demyelination

Multiple sclerosis (MS) (which means ‘many scars’) is an incurable neurological condition. It is characterised by an abnormal immune response that targets myelin, a fatty material responsible for insulating the nerve fibres in the central nervous system (CNS) (which comprises the brain, spinal cord and optic nerves) (Better Health Channel 2019).

When the immune system mistakenly attacks the myelin, it is destroyed in a process known as demyelination. This leaves the underlying nerve exposed, leading to inflammation and scarring (lesion formation) (MSRA 2020; Better Health Channel 2019).

This damage disrupts the nerve impulses, impairing their ability to transmit messages between the brain and the body. As a result, the individual will experience a variety of neurological and other symptoms (Better Health Channel 2019).

While the brain will attempt to heal the scarred tissue, some damage may be irreversible. Consequently, the brain will suffer atrophy (loss of volume) (Better Health Channel 2019).

Types of Multiple Sclerosis

MS is an unpredictable disease and may progress differently depending on the individual (MS Australia 2020a).

There are three main clinical courses (‘types’) of MS:

  1. Relapsing-remitting MS (RMMS) is the most common form of MS, accounting for about 85% of initial diagnoses. RMMS causes flare-ups of active disease activity, which are then followed by partial or total remission where the disease does not appear to be worsening. Symptoms may completely disappear during remission periods, or the individual may only partially recover from flare-ups.
  2. Primary-progressive MS (PPMS) is less common. It is characterised by a gradual worsening of symptoms from the onset, causing increased disability. There are generally no remission periods.
  3. Secondary-progressive MS (SPMS) occurs when an initial RMMS diagnosis begins to cause progressive worsening of symptoms. Most people with RRMS will eventually develop SOMS, however, this may take several years or even decades.

(Better Health Channel 2019; MS QLD 2019a; MS Australia 2020a)

multiple sclerosis Relapsing-remitting diagram
multiple sclerosis Primary-progressive diagram
multiple sclerosis Secondary-progressive diagram

(Diagrams adapted from MS Australia 2020a; Lublin et al. 2014)

What Causes Multiple Sclerosis?

A singular cause of MS is unknown, however, it is believed that the condition is linked to an interaction between several factors, including:

  • Genetics
  • Infection with certain viruses, including Epstein-Barr virus
  • Living in an area further from the equator
  • Lack of vitamin D
  • Smoking.

(Better Health Channel 2019)

How Is Multiple Sclerosis Diagnosed?

As there is no single test for diagnosing MS, it may take years to reach a conclusion (Healthdirect 2020).

Furthermore, many of the early symptoms are non-specific, which increases the difficulty of making a diagnosis (Better Health Channel 2019).

Patients may undergo a variety of tests in order to establish a diagnosis, including:

  • Neurological examination
  • Blood tests to rule out differential diagnoses
  • Magnetic resonance imaging (MRI) to assess for the presence of scarring
  • Lumbar puncture to assess the cerebrospinal fluid.

(Better Health Channel 2019)

In order for MS to be diagnosed, there must be evidence of different areas of damage in the CNS that have occurred at different times (Healthdirect 2020).

While it is possible for children to be diagnosed with MS, the majority of people diagnosed are adults between 20 and 40 years of age. About 75% of those living with MS are women (Better Health Channel 2019).

Symptoms of Multiple Sclerosis

The symptoms of MS vary between individuals and are often unpredictable, with no two cases the same. Generally, symptoms depend on the area of the CNS that has been affected (Better Health Channel 2019).

The prevalence of depression is three times higher in people living with MS than in the general population, with half of those diagnosed experiencing depressive episodes (MS QLD 2019b).

MS Symptoms can be categorised into several areas. People living with MS may experience a combination of the following:

Motor control symptoms
  • Ataxia
  • Walking difficulties
  • Impaired balance or coordination
  • Muscle spasms and tremors
  • Muscle weakness
  • Speech difficulties (slurring or slowing)
  • Dysphagia
  • Breathing difficulties
  • Heart issues
  • Muscle spasticity
  • Nerve pain
  • Uhthoff’s phenomenon (the acute onset of symptoms such as nerve pain caused by increased body temperature)
  • Optic neuritis (inflammation of the optic nerve)
  • Headaches
  • Extreme tiredness, often accompanied by heat sensitivity
Other neurological symptoms
  • Visual disturbances (e.g. blurred vision, double vision, impaired depth perception, loss of sight)
  • Altered sensations (e.g. pins and needles, numbness, neurological pain, heat or cold sensitivity, discomfort)
  • Dizziness or vertigo
  • Neuralgia
Bladder and bowel dysfunction
Neuropsychological symptoms
  • ‘Brain fog’
  • Memory and concentration issues
  • Disruptions to processing speed and ability
  • Impaired cognitive function
  • Emotional changes
  • Anxiety
  • Depression
  • Sleeping issues

(Better Health Channel 2019; MS Australia 2018, 2020b)

Multiple Sclerosis Relapses

Relapses are characterised by the sudden onset of a new or existing symptom that:

  • Lasts for over 24 hours (usually several weeks)
  • Has no other clinical explanation apart from MS
  • Occurs at least 30 days after the onset of a previous relapse.

(MS Australia 2020c)

What Is The Goal Of Treatment?

As MS is incurable, the main goals of treatment are to maximise the patient’s quality of life by:

  • Minimising relapses
  • Eliminating inflammation
  • Preventing new lesions from forming
  • Decreasing brain atrophy
  • Restoring function
  • Reducing the overall impact of symptoms on the patient’s life.

(Better Health Channel 2019)

Treatments that may help to manage and relieve symptoms include:

  • Disease-modifying therapies, which target the immune system to decrease the frequency and severity of attacks, reducing the progression of the disease
  • Immunosuppressants, which inhibit the immune system’s activity
  • Steroid medicines, which reduce symptoms during a relapse (by decreasing inflammation in affected areas of the body)
  • Complementary therapies
  • Symptomatic treatments, which target specific symptoms.

(MS Australia 2021; Better Health Channel 2019)

Patients should also be encouraged to:

  • Maintain a healthy weight
  • Maintain a healthy diet
  • Avoid smoking
  • Limit alcohol consumption
  • Keep their mind and body active
  • Practice stress-management techniques (as stress increases the risk of relapse)
  • Undergo regular treatment follow-ups, six-monthly treatment reviews and annual MRI scans.

(Better Health Channel 2019)

The Role of the Healthcare Professional in Multiple Sclerosis Care

multiple sclerosis health professional showing patient mri

Treatment of MS may involve an interprofessional team, depending on the patient’s symptoms. The health professionals involved may include a:

  • Nurse
  • MS specialist
  • Neurologist
  • Physiotherapist
  • Occupational therapist
  • Continence advisor
  • Speech therapist
  • Dietician
  • Psychologist or neuropsychologist
  • Rehabilitation team
  • Pharmacist
  • Urologist.

(Multiple Sclerosis Trust 2019; Better Health Channel 2019)


The unpredictable nature of MS and lack of strong diagnosis methods poses challenges for healthcare professionals.

Therefore, it is imperative that when caring for these patients we adopt an interprofessional and individualised approach to achieve the highest level of patient care.

Additional Resources


Test Your Knowledge

Question 1 of 3

Finish the sentence: People living with MS are ... as likely to experience depression.


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Sally Moyle View profile
Sally Moyle is a rehabilitation nurse educator with Epworth HealthCare. She has completed her masters of nursing (clinical nursing and teaching) and has experience in many nursing sectors including rehabilitation, orthopaedic, neurosurgery, emergency, aged care and general surgery. Sally is passionate about education in nursing in order to produce the best nurses possible.
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