What to Know About MS and Fatigue

Fatigue is one of the most common and disabling symptoms of multiple sclerosis

Medically reviewed by Brigid Dwyer, MD

Fatigue in multiple sclerosis (MS) is the depletion of physical and/or mental energy that interferes with usual or desired daily activities. It's a widespread symptom, affecting up to 80% of people with MS, and can be severe in up to 70%.

Symptoms of MS, including fatigue, manifest when a person's immune system malfunctions and attacks the fatty tissue (myelin) surrounding nerve fibers within the brain, spinal cord, and eyes.

In addition to being a direct result of MS, fatigue can be secondary to other factors like MS medication side effects, depression, or disturbed sleep.

This article explores the causes of fatigue in MS and how it can be effectively managed through energy-conserving strategies, lifestyle behaviors, and, sometimes, medication. 

What Does MS Fatigue Feel Like?

MS fatigue differs from excessive sleepiness or the sluggishness people experience after a long day of working, attending school, or caring for young children. It's more severe, persistent, and associated with extreme energy draining.

Individuals with MS may describe fatigue as feeling like they have the flu, are constantly jet-lagged or hungover, or are weighed down by cement. Brain fog is also commonly reported. With brain fog a person may feel mentally "fuzzy" or "spacey," easily distracted, and even disoriented.

Depending on the severity, MS fatigue disrupts a person's ability to perform daily activities like getting dressed, doing laundry, paying bills, going to work, and engaging in pleasurable activities like reading a book or attending social functions.

What Causes MS Fatigue?

The lack of energy seen with MS fatigue can be caused by the disease itself or other factors like medications, depression, or sleep problems.

Primary Fatigue

MS fatigue unique or specific to the disease itself is called lassitude. It's unclear the exact underlying processes that cause primary MS fatigue.

Structural brain abnormalities and dysfunctional nerve signaling from demyelination (loss of myelin, the insulating sheath around nerve fibers) involving tissue deep within the brain (gray matter) likely play a role.

An imbalance in the metabolism of the brain chemical dopamine, hormonal disturbances, and the release of inflammatory proteins called cytokines could also contribute.

The following features mark lassitude in MS:

• It occurs on a daily or near-daily basis and comes on suddenly.

• It can be felt early in the morning, even after a restful night's sleep.

• It's usually out of proportion to prior activity levels.

• It tends to worsen as the day progresses.

• It usually disrupts a person's daily routine.

Interestingly, regardless of a person's degree of physical disability, fatigue can manifest anytime during MS. For some people, fatigue is their first symptom.

In addition, fatigue is more commonly reported in people with relapsing-remitting MS (RRMS), marked by a fluctuating increase and decrease in symptoms, than primary progressive MS (PPMS), a progressive form of MS. This suggests that its presence is not related to objective neurological progression (e.g., walking problems).

Related: Early Warning Signs of Multiple Sclerosis (MS)

Secondary Fatigue

Secondary fatigue stems from a factor or condition that can be related or unrelated to MS.

Common causes of secondary MS fatigue include:

• MS medications, namely interferon drugs (disease-modifying therapies), medicines used to treat symptoms such as spasticity (muscle tightening/spasms), pain, or bladder problems

• Depression, which is characterized by persistent sadness and a lack of interest in activities a person once enjoyed that affects up to 50% of people with MS in their lifetime.

• Sleep challenges unique to MS, like frequent nighttime urination and pain from spasticity

• Other health conditions, namely anemia, thyroid disease, sleep disorders (e.g., sleep apnea or restless legs syndrome), and vitamin deficiencies (e.g., vitamins D or B12)

Triggers of Fatigue

Several external or internal factors can precipitate or aggravate primary or secondary MS fatigue, namely stress, hot/humid weather, or inactivity, leading to body deconditioning.

Related: Why Heat May Worsen MS Symptoms

MS Fatigue Scale

Various scales can be used to understand a person's degree of MS fatigue and its impact on day-to-day life. These scales offer a standardized way of quantifying MS fatigue. They can be used in research studies or clinical practice, meaning people can complete the scale and share results with their MS healthcare provider.

Two commonly used MS fatigue scales include the Fatigue Severity Scale and the Modified Fatigue Impact Scale.

Fatigue Severity Scale (FSS)

The FSS is a nine-question scale that measures the severity of a person's fatigue. Responses to the questions range from 1 ("strongly disagree") to 7 ("strongly agree"). The total FSS score is the average score over the nine questions, with a higher score indicating more severe fatigue.

Modified Fatigue Impact Scale (MFIS)

The MFIS comprises 21 questions divided into three categories—physical, cognitive, and psychosocial—with question scores ranging from 0 (never) to 4 (almost always).

While slightly longer than the FSS, a potential benefit of the MFIS is that scores for each category can be analyzed to more precisely target the impact of an individual's fatigue on their lifestyle.

Related: Self-Assessment of Multiple Sclerosis Symptoms

Complications

If not managed, MS fatigue can drastically affect a person's quality of life and ability to engage in usual and desired activities, like completing household chores, working, and caring for children.

Other potential complications of MS fatigue include:

• Aggravating underlying psychological diseases, namely depression and anxiety

• Changes in self-identity and social isolation

• Increased risk for falls and subsequent injuries

Related: Symptoms and Complications of Advanced Multiple Sclerosis (MS)

Treatment for MS Fatigue

Unfortunately, a nap or a strong cup of coffee won't usually do the trick in easing a person's MS fatigue. Instead, it usually takes daily effort and several nondrug therapies to tackle MS fatigue. In some instances, medication is needed to obtain sufficient relief.

How to Manage MS Fatigue at Home

The following home remedies and lifestyle behaviors can help you manage MS fatigue:

• Stay cool by drinking cold water throughout the day, wearing lightweight clothes, and turning on the air-conditioning in your home. Also, consider purchasing a handheld misting fan or cooling vest.

• Get a good night's sleep by creating a sleep ritual, such as going to bed and getting up at the same time every day. Also, talk with an MS provider about treating symptoms that may interfere with sleep, like spasticity or bladder problems.

• Conserve energy to find the right balance among work, rest, and pleasure. Try scheduling essential activities (e.g., working, cooking, or caring for your children or pets) during high-energy times. Depending on your degree and cause of fatigue, you might also consider using a mobility aid like a cane, walker, or manual/motorized wheelchair.
  

• Devise an exercise regimen under the guidance of a physical therapist, as physical activity can improve fatigue. Try to incorporate resistance training and aerobic exercises into your regimen.

• Cope healthily with stress by joining a support group and participating in cognitive behavioral therapy or mindfulness-based training.

Related: Can Stress Trigger Multiple Sclerosis?

Medications

There are no Food and Drug Administration (FDA)–approved medications for treating fatigue in MS. However, the following drugs are sometimes prescribed off-label, meaning they were FDA-approved for another condition but reportedly work for MS fatigue as well. They will sometimes be prescribed if a person's fatigue is still debilitating despite nondrug therapies.

Keep in mind that while used commonly, the scientific evidence backing their effectiveness is scant. Moreover, the medications in the following list have potential side effects, which can limit their use:

• Symmetrel (amantadine) is an antiviral drug used to prevent or treat influenza (flu) infections and Parkinson's disease. Its mode of action is unknown, although it may lead to more significant amounts of dopamine release in the brain.

• Provigil (modafinil) improves wakefulness in adults with excessive sleepiness from narcolepsy, obstructive sleep apnea, or shift work disorder. Like amantadine, its mode of action is unknown but may have a dopamine effect.

• Ritalin (methylphenidate) is a nervous system stimulant used to treat narcolepsy and attention deficit hyperactivity disorder (ADHD). It increases dopamine release in the brain.

• Ampyra (dalfampridine) is a potassium channel blocker that increases muscle strength. It effectively improves walking speed in MS and may also improve fatigue.

• Antidepressants—for example, Prozac (fluoxetine)—may improve fatigue, mainly if depression contributes to it.
  

Learn More: Medications That May Help MS Fatigue

When to Talk to a Healthcare Provider

Call a healthcare provider or your neurologist if you are experiencing new or recurring fatigue that negatively impacts your daily quality of life or ability to function.

A healthcare provider can determine whether your fatigue is related to MS, another health condition, or a reversible trigger (e.g., fever from an infection). Based on the suspected cause, you and your provider can devise a treatment plan together.

If your fatigue is unusually severe—for example, you are so weak you are having trouble walking—call your neurologist immediately or go to your nearest emergency room.

Related: Living With Multiple Sclerosis

Summary

Fatigue is a silent burden in multiple sclerosis (MS) and is reported as one of the most common and debilitating symptoms. More than sleepiness, MS-related fatigue is a lack of physical and/or mental energy, regardless of activity level, and often not relieved with rest.

Primary fatigue in MS (lassitude) develops from abnormalities within the brain and spinal cord, whereas secondary MS fatigue stems from factors like medication side effects, sleep problems, and depression.

Treating fatigue in MS requires a thoughtful and multifaceted approach and depends on the impact on functional ability and quality of life. Therapies for fatigue often involve energy conservation strategies, lifestyle changes (e.g., exercise and sleep routine), and sometimes, medication.

Read the original article on Verywell Health.