Fatigue Severity Scale (FSS): Free Self-Assessment
Fatigue is more than just feeling tired. It is a persistent, overwhelming exhaustion that can drain your motivation, impair your concentration, and make even simple daily tasks feel unmanageable. The Fatigue Severity Scale (FSS) is one of the most widely used clinical tools for measuring how severely fatigue affects your daily functioning. Developed by Krupp et al. in 1989 and cited over 7,000 times in academic research, it was originally designed for people with multiple sclerosis and lupus but is now used across a wide range of neurological and medical conditions.
This free self-assessment takes just two minutes. If you also experience difficulties with memory or attention, you may find our Cognitive Failures Questionnaire useful alongside this scale.
Take the Fatigue Severity Scale
Fatigue Severity Scale (FSS)
9 statements about fatigue · Takes 2 minutes
Instructions: Read each statement and rate how much you agree, based on your experience over the past week. 1 means you strongly disagree and 7 means you strongly agree.
Your answers are not stored or transmitted. Everything runs in your browser.
Low Fatigue
Borderline
Significant Fatigue
Severe Fatigue
Reducing Cognitive Fatigue Day to Day
When fatigue drains your mental energy, even small tasks feel overwhelming. Recallify helps by capturing information through voice, automatically extracting tasks, and providing smart reminders, so you can conserve cognitive resources for what matters most.
What Does the FSS Measure?
The FSS consists of nine statements about fatigue and its impact on motivation, physical functioning, duties, and social life. You rate each statement from 1 (strongly disagree) to 7 (strongly agree) based on your experience over the past week. The mean score across all nine items gives a result between 1.0 and 7.0.
The original validation study found a mean score of 2.3 in healthy adults, while patients with MS averaged 4.8. A mean score of 4.0 or above is widely used as the threshold for clinically significant fatigue. The FSS has strong internal consistency (Cronbach’s alpha of 0.88) and good test-retest reliability, making it a stable measure of how fatigue affects your life over time.
How Is the FSS Scored?
Your total is calculated by adding all nine item scores and dividing by nine, giving a mean between 1.0 and 7.0. We display four interpretive bands: low fatigue (1.0 to 2.9, consistent with the healthy population average), borderline (3.0 to 3.9, above average but below the clinical threshold), significant fatigue (4.0 to 5.4, above the clinical cut-off), and severe fatigue (5.5 to 7.0, substantial impact across daily life). A large Swiss validation study confirmed the 4.0 cut-off across multiple conditions including MS, stroke, Parkinson’s, and narcolepsy.
Why Fatigue Matters for Cognitive Health
Fatigue does not just affect your body. It directly impairs cognitive function, slowing processing speed, reducing working memory capacity, and making it harder to plan, organise, and follow through on tasks. For people living with MS, acquired brain injuries, or ADHD, cognitive fatigue is often the most debilitating daily symptom. Understanding the severity of your fatigue is a practical first step toward managing it, whether through pacing strategies, structured routines, energy management, or using external tools to reduce cognitive load.
How Recallify Helps When Fatigue Drains Your Energy
When fatigue makes it hard to think clearly, having a reliable system to fall back on makes a real difference. Recallify captures information through voice recordings so you do not have to type or write when your energy is low. It automatically extracts tasks, provides structured reminders and daily planning, and offers a searchable memory bank you can query in natural language. The result is less mental effort spent trying to remember and organise, and more energy preserved for the things that matter.
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Frequently Asked Questions
Is this fatigue test a medical diagnosis?
No. The FSS is a screening tool that measures how fatigue affects your functioning. It cannot diagnose the cause of your fatigue. Many conditions can cause significant fatigue, including MS, brain injury, sleep disorders, anaemia, thyroid problems, depression, and others. If your score is 4.0 or above, we would encourage you to speak with your GP.
What is a normal FSS score?
The average score for healthy adults is approximately 2.3. A mean score of 4.0 or above is generally considered the threshold for clinically significant fatigue. Scores between 3.0 and 3.9 are borderline and may warrant monitoring.
Is fatigue the same as sleepiness?
No. Fatigue and sleepiness are related but distinct. Sleepiness is the tendency to fall asleep, while fatigue is a persistent feeling of exhaustion and reduced capacity for physical or mental effort. You can be severely fatigued without feeling sleepy, and vice versa. The FSS specifically measures fatigue, not sleepiness.
Can I take this if I have MS, a brain injury, or ADHD?
Yes. The FSS was originally developed for MS and has since been validated for use with brain injury, stroke, Parkinson’s, chronic fatigue syndrome, and many other conditions. Fatigue is also extremely common in ADHD, though less widely recognised. Your results can be a useful conversation starter with your clinician.
How often should I take the FSS?
The FSS asks about the past week, so you can repeat it weekly or fortnightly to track changes. This is especially useful if you are trying new management strategies, starting medication, or adjusting your routine, as it gives you a way to measure whether fatigue is improving.
Are my answers to this quetionnaire stored?
No. This tool runs entirely in your browser. No answers or scores are stored, transmitted, or shared.