Beyond Tired: Why MS Fatigue Feels Different
If you have MS, fatigue is more than just feeling tired
By Deborah Hauss, Senior Staff Writer, Communications
Information overload, emotional stress, or just working at a computer for hours can lead to mental fatigue, something we all experience. But for people living with multiple sclerosis, fatigue is an entirely different challenge. More than just feeling tired, fatigue in MS is a deep, persistent exhaustion that doesn’t fully improve with rest and often interferes with everyday life.
What Is fatigue, really?
Even though fatigue is one of the most common symptoms of MS, it remains one of the least understood. Part of the challenge is that it’s difficult to measure. Because there are over 250 different instruments available to assess fatigue, inconsistencies arise in how it is defined and assessed. Some define it as a lack of energy, others as a desire to rest, and some even mix it with cognitive difficulties like memory problems or slow thinking.
Glenn Wylie, DPhil, director of the Rocco Ortenzio Neuroimaging Center at Kessler Foundation, defines the symptom as a signal the brain generates when the reward for a given activity no longer merits the effort required to do that work.
“MS-related fatigue differs in quantity rather than in quality. If you have a neurodegenerative disease like MS, then everything you must accomplish takes more effort,” he explains. This means that the “cost” of completing everyday tasks is higher for people with MS, making them feel fatigued much faster than those without the disease. That imbalance—where the effort keeps increasing but the reward stays the same—causes a feeling of exhaustion. Everyday tasks, like grocery shopping, can become overwhelming because they require extra mental and physical effort.
Video courtesy of The Royal Society
How do we measure fatigue?
Dr. Wylie points out that most fatigue assessments rely on asking people to reflect on how fatigued they’ve felt over time, but this retrospective self-reporting method has flaws.
- People may remember recent fatigue more than fatigue from earlier in the week
- Some may focus on their worst days, while others average out their experiences
- Everyone has different baselines—what feels like extreme fatigue for one person might feel normal for another
To get a clearer picture, researchers at Kessler Foundation are studying real-time fatigue by having participants rate their fatigue before and after short cognitive tasks in an MRI scanner. This method helps pinpoint how fatigue builds up over time and how the brain reacts to it.
Ways to manage MS-related fatigue
Dr. Wylie and his team are also investigating various management strategies, including motivation techniques, exercise, and medication.
- Motivation and rewards can help. Recent studies indicate that fatigue is linked to the balance between effort and reward, leading researchers to explore whether increasing motivation can help reduce feelings of exhaustion. Positive reinforcement, whether through small incentives, mental encouragement, or external motivators, might help counteract fatigue and make tasks feel more manageable
- Exercise can make a difference. While it may seem counterproductive to suggest exercising when fatigued, eventually, exercise lowers fatigue levels by improving overall energy regulation and fitness
- Medications may lower fatigue levels. An area of research in its early stages explores disease-modifying therapies using medications that slow the progression of MS and may also help reduce baseline fatigue in individuals with the condition
Fatigue management in MS is an ongoing journey, and the best approach can differ for everyone, says Dr. Wylie. “We are gaining a better understanding of how fatigue works and discovering new ways to help people with MS improve their energy levels and quality of life.”
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