Multiple Sclerosis Society of Canada


Symptoms of MS are unpredictable and vary greatly from person to person, and can fluctuate within the same person from one time to the next.

What causes symptoms in MS?

MS attacks the protective covering — myelin — of the brain and spinal cord, causing inflammation and often damaging the myelin in patches. When this happens, the usual flow of nerve impulses along nerve fibres (axons) is interrupted or distorted. The result may be the wide variety of MS symptoms, depending upon what part or parts of the central nervous system are affected. Not all people with MS will experience all symptoms and often the symptoms will improve during periods of remission.

There are a variety of ways to manage symptoms, ranging from pharmacological treatments to non-medicinal strategies such as physiotherapy, occupational therapy, exercise programs and alternative and complementary treatments. The following is a list of some of the more common MS symptoms.


Balance, and vertigo, or dizziness problems are common in MS and their management can be difficult. These symptoms are caused by lesions in the areas that coordinate visual, spatial and other input needed to produce and maintain equilibrium. Balance and dizziness may present as symptoms of a relapse, or may be permanent, and can pose increased safety risk for falls.

Some balance problems can be overcome with a walking aid. Walking aids should only be used with the instruction of a trained professional to ensure proper gait alignment. A home assessment for safety conducted by an occupational therapist can be helpful to identify potential hazards and to suggest strategies for a safe approach to activities of daily living.

Key Healthcare Professionals: Neurologist, MS nurse, occupational therapist, physiotherapist

Bladder Dysfunction

MS lesions in the brain or spinal cord can disrupt the normal bladder process by interfering with the transmission of signals between the brain and urinary system.

Treatment of bladder dysfunction depends on the type of dysfunction a person is experiencing.

North American Education Program 2015: Managing Bladder and Bowel Issues in MS

Please see Bladder Dysfunction and MS to learn about the different types of dysfunction, and how they are treated.

See here for a list of symptom management medications.

Key Healthcare Professionals: Family physician, urologist, neurologist, and MS nurse.

Bowel Dysfunction

Bowel dysfunction in MS most commonly presents as constipation but can include diarrhea and incontinence. Constipation is in MS is caused by interruption of neural pathways. Decreased mobility and poor hydration can also aggravate bowel problems.

North American Education Program 2015: Managing Bladder and Bowel Issues in MS

Changes in bowel habits should be assessed to rule out non-MS causes, and age appropriate bowel screening should be done.

Most people can develop an improved bowel performance within 3-4 weeks of introduction of the suggested interventions.

Pharmacologic interventions should be used as a last resort (bulk and fiber agents, stool softeners, lubricants, and stimulants).

See Understanding Bowel Dysfunction for more information.

Key Healthcare Professionals: Family physician, MS nurse, nutritionist, pharmacist and if required, a gastroenterologist

Cognitive Impairment

Cognitive changes can be one of the earliest manifestations of demyelination associated with MS and will affect between 40-70% of people. Memory problems, especially short term memory, are the most common.

MRI studies have demonstrated a clear relationship between MS lesions and cognitive problems.

Research has also shown that MS can cause a reduction in brain size (or atrophy). This atrophy is closely linked to the presence of cognitive difficulties and may be a more likely cause of cognitive problems than brain lesions.

See Cognition and MS for more information.

Key Healthcare Professionals: Family physician, MS nurse, psychologist, neuropsychologist, occupational therapist speech/language pathologist


Depression is more prevalent in people with MS than in the general population and may be of a reactive nature, not only at the time of diagnosis but throughout the course of the disease. Research also suggests that depression may be related to physiological tissue changes and linked to the disease process itself.

Fatigue can complicate the picture of depression but a key indicator may be low mood.

Depression responds well to antidepressant medication, and counseling.

See here for a list of symptom management medications.

Key Healthcare Professionals: Family physician, MS nurse, psychologist, psychiatrist, neurologist, social worker.


MS fatigue can be one of the most disabling symptoms of MS; up to 90% of people with MS experience fatigue. Fatigue can be a primary symptom (due to active inflammatory disease) or a secondary symptom (the result of other symptoms or conditions such as sleep disorders, depression, or muscle weakness).

Fatigue can often be improved by changes in lifestyle. Energy conservation counseling, mobility aids (scooter or wheelchair), air conditioning, regular exercise and medication are all ways to manage fatigue.

See Fatigue and MS.

Key Healthcare Professionals: Family physician, MS nurse, neurologist, occupational therapist, physiotherapist, social worker.

Gait (difficulty in walking)

Several factors may contribute to gait disturbance such as muscle weakness, spasticity, balance and co-ordination problems, fatigue and pain. Gait is governed by many neural pathways and the disseminated nature of MS makes it possible for many important nerve tracts to be disrupted.

Physical and occupational therapy can be most helpful in assessing gait and recommending strategies, aids, and home modifications to promote better gait and safety in activities of daily living that are compromised by gait disturbance.

Key Healthcare Professionals: Neurologist, physiotherapist, occupational therapist, family physician.

Optic neuritis

Optic neuritis, inflammation of the optic nerve, presents as sudden onset of visual blurring or loss of vision in one eye, particularly in the central visual field. Eye movement may bring on pain, light flashes, or other visual symptoms.

Optic neuritis is the initial symptom for 16% of people with MS and is a common occurrence during the course of the disease.

Onset to peak presentation usually happens within 4 days, and most recovery is usually achieved by about 5 weeks, although some improvement may continue for up to a year. The pain usually resolves more quickly than the visual acuity. See Managing Pain and Sleep Disorders.

Treatment with corticosteroids may be introduced and is especially effective at reducing the pain.

Key Healthcare Professionals: Neurologist, neuro-ophthalmology, ophthalmologist, optometrist


About 50% of people with MS will experience some MS related pain during the course of the disease and it can take several forms.

Pain in MS can be managed, but it requires careful identification of the type of pain, and persistence in determining the best medication and/or dosage. It frequently requires multidisciplinary input and, if severe, may benefit from the expertise of a pain clinic.

See Pain and MS and Managing Pain and Sleep Disorders

Key Healthcare Professionals: Family physician, nurse, neurologist, occupational and physical therapists, pain clinic.

Paroxysmal Symptoms

Paroxysmal symptoms refer to a sudden onset of a neurological symptom, or cluster of symptoms that may last over seconds to minutes, repeating a few to very many intervals per day. They can occur at any time in the course of MS and may vary in intensity and frequency, with or without pain. When these symptom clusters occur over several days, it may be considered to be an MS relapse. They may include (but are not limited to) trigeminal neuralgia, tonic spasms, weakness, dysarthria and ataxia, visual disturbance, numbness and other sensory disturbance, and Lhermitte’s sign.

Management includes ruling out non MS causes of paroxysmal phenomena. Anticonvulsants , particularly carbamazepine are usually helpful. Gabapentin may be helpful as can be benzodiazepines such as clonazepam.

Key Healthcare professionals: Neurologist, MS nurse.

Sensory Impairment, Numbness / Tingling

Numbness is the most common sensory symptom, and usually occurs with an onset in one or more limbs. Commonly people awake with abnormal sensation in a portion of a limb, which gradually spreads inward toward the trunk, increasing in extent and intensity. It may extend to include the body trunk.

Sometimes the sensory disturbance can be painful. Achy, burning sensations, a feeling of tightness or banding – these are known as ‘dysesthesias’.

Dysesthesias usually respond to anti-seizure medication such as carbamazepine. Amitriptyline can be useful as can be gabapentin and some of the newer pregabalin medications.

See Managing Pain & Sleep Issues in MS.

Key Healthcare Professionals: Neurologist, MS nurse, occupational therapy

Sexual Dysfunction

MS can affect sexual feelings and functions both directly (primary sexual effects) and indirectly (secondary and tertiary sexual effects). The central nervous system makes sexual arousal possible; the brain, sexual organs, and other parts of the body send messages to each other along nerves that run through the spinal cord. MS-related damage to these nerve fibres can directly impair sexual feelings or sexual responses.

Talk about it. It can be difficult but talking about sexual issues with your partner is crucial to intimate relations when MS changes the body and the mind. Confiding in your partner deepens intimacy and may go a long way toward resolving fears.

Talk to your healthcare team. An easy way to begin the conversation with your doctor is by requesting regular checkups related to sexual health. Many sexual problems associated with MS can be medically managed but the first step is talking to your doctor or MS nurse.

Identifying treatment strategies. There is no single site for sexual response in the human nervous system. The nerves that orchestrate it are spread throughout the brain and spinal cord. This means that there are many pathways where MS lesions might disrupt nerve messages for sexual activities or feelings.

See Intimacy and Sexuality in MS.

Key Healthcare Professionals: Neurologist, family physician, psychologist, urologist, gynecologist.

Spasticity (see also Pain)

Spasticity in MS is related to alterations in the normal excitory / inhibitory balance on the nerves responsible for movement, caused by lesions in central pathways and can be both intermittent (spasms) and tonic (stiffness). Flexor and extensor spasms can be very troublesome, especially at night, adding to fatigue. Spasticity can also present challenges in walking, seating, and can interfere with hygiene and nursing care in individuals with advanced MS.

Implementation of a stretch program, assessment for gait, mobility and safety is important. For those with marked disability, it may be necessary to review seating. Spasticity can also be improved with medication, on review with the treating physician.

Key Healthcare Professionals: Neurologist, physiotherapist, occupational therapist, MS nurse.


Tremor is a movement disorder with an involuntary, relatively rhythmic pattern, related to demyelination in the cerebellum and its pathways. It includes intention tremor, or tremor triggered by voluntary movement, affecting any muscle group including arms, legs, trunk, head, vocal cords, jaws lips, and tongue. Tremor in MS is difficult to manage and is not reliably improved by medication. Tremor can add significantly to both fatigue and functional disability in MS.

Consultation with occupational and physical therapy around issues related to activities of daily living and safety may be helpful. Medications for tremor in MS have limited benefit.

Key Healthcare Professionals: Neurologist, occupational therapist.

Uhthoff's Phenomena (Heat Intolerance)

Many people with MS experience sensitivity to increased body temperature. Demyelinated fibers in the central nervous system can be very sensitive to even small elevations of core body temperature resulting in conduction delays or even conduction block. This sensitivity can be brought out by sunbathing, exercise, hot baths, emotion, fatigue, fever, or any other factor associated with an increase in body core temperature. Any MS symptom can present this way.

Symptoms disappear with rest and cooling.

Avoidance is the best defense, and when unavoidable, minimum exposure followed by cooling strategies should be sought. Generally the effects of heat exposure are reversed with rest and cooling and do not carry a long term consequence. A number of manufacturers make cooling vests, hats, etc. The following is a suggested list of manufacturers and suppliers of "cooling” clothing. These links are provided for your interest only – the MS Society does not endorse any supplier or manufacturer.

Key Healthcare Professionals: Neurologist, MS nurse.


Weakness is a common finding in MS. Motor weakness is related to impaired nerve conduction due to inflamed and / or damaged central nerve pathways. When testing for muscle weakness it is important to consider factors like fatigue and environmental issues such as room temperature and time of day.

Gait assessment is important in light of leg weakness as a compromised gait adds strain to the back, often causing back pain.

Physiotherapy can suggest a stretch and strengthen program to maximize muscle potential and improve general conditioning.

Key Healthcare Professionals: Neurologist, MS nurse, physiotherapist, occupational therapist.

Other MS Symptoms

Dysarthria, or difficulty speaking

Dysarthria result from a variety of neurological disturbances and can range from mild difficulty annunciating words to sounding like speaking with marbles in one’s mouth. Speech can sound garbled, and unclear.

Weakness, spasticity, and ataxia of the muscles of the lips, tongue, mandible, soft palate, vocal cords and diaphragm can all contribute to this problem. It may present as slow or garbled speech, difficulty with voice volume and projection, or difficulties chewing and even swallowing. Dysarthria may also present in episodic occurrences that recur up to several times a day for short periods of time.

A speech and language pathologist may be able to assess and suggest interventions to improve communication ability.

Key Healthcare Professionals: Speech language pathologist

Dysphagia (difficulty swallowing)

Dysphagia can commonly be mild choking, most often with liquids but can also be quite severe. The variation of MS involvement offers the potential for a wide variety of swallowing difficulties: a delay in triggering the swallow response is common, causing difficulty with liquids. A weakened pharyngeal wall contraction may result in food being left behind after a swallow and food aspiration in small amounts can pose risk of infection to lungs.

Treatment will focus on rehabilitative strategies and may include interventions in posture, thermal-tactile stimulation, counseling about eating habits, and voluntary swallow strategies.

Identification and assessment of swallowing difficulties by speech language pathologist, using videofluoroscopy may be very useful.

Key Healthcare Professionals: Speech language pathologist, dietitian/nutritionist

Dry Mouth

Dry mouth in MS is usually related to side-effects of medications.

Proper hydration, lozenges and chewing gum may help moderate this medication side effect. As with any new symptom, it is important to check with the GP to rule out non-MS causes of the problem.

Key Healthcare Professionals: Family physician, pharmacist.

Hormonal Influences for women with MS

A worsening or aggravation of existing symptoms, or even the emergence of new ones just before the menstrual cycle, followed by an improvement during menstruation or immediately following, can happen. Some of the change may be related to changes in core body temperature as happens with ovulation.

During pregnancy it is observed that MS can often seem to remit with an improvement in symptoms and the disappearance of relapses. There is however a slight increased risk of relapse in the first three months immediately postpartum.

In extreme cases, consultation with a gynecologist may be helpful.

Key Healthcare Professionals: Family physician, MS nurse.

Inappropriate Affect (pseudo bulbar affect, emotional incontinence, involuntary emotional expression disorder-IEED)

Uncontrolled or involuntary laughter and/or crying can be a distressing symptom in MS. Once it starts, it can be very hard to stop. This can cause distress and much embarrassment for the person experiencing it, and can also result in mistaken information cues for the person observing it.

It is thought to be related to lesions in the cortex responsible for emotional control aspects, the bulbar nuclei, the physiological effector, and the hypothalamus which integrates the two. In this context, people can exhibit sudden and exaggerated expressions of emotion (laughter and crying) that may or may not be demonstrative of their mood at the time.

This condition, though not caused by depression, can be effectively treated with relatively small doses of a number of drugs including some members of the tricyclic and SSRI families.

Key Healthcare Professionals: Neurologist, neuropsychiatrist

Poor coordination or incoordination

Poor coordination in MS results from cerebellar involvement and can be one of the most disabling symptoms of MS. It often co-exists with tremor, and balance difficulties. Errors in rate, range, direction, and force of movement are characteristic in these cases, making the simplest of daily activities like walking, pouring liquids, eating, and personal hygiene very difficult.

Walking aids, home safety assessment with focus on bathroom, kitchen and stairs.

Key Healthcare Professionals: Neurologist, occupational and physical therapists.

Mood Lability / Bipolar Affective Disorder

Mood swings alternating between mania and depression, known as bipolar disorder, are more common in MS than in the general population. Bipolar disorder may occur as a disease symptom, or may occur in response to drug treatment, most commonly, steroids.

Lithium, carbamazepine, and valproate are the most commonly used mood stabilizers, as well as gabapentin and lamotrigine. Data on the use of these drugs in MS is mostly anecdotal and large studies are lacking. Of note, lithium can produce increased urine output and so may be poorly tolerated by people with bladder dysfunction.

Screening for additional mental health issues such as depression should be considered.

Key Healthcare Professionals: Family physician, neurologist, neuropsychiatrist.

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