Assess your fatigue levels using the validated 9-question Fatigue Severity Scale questionnaire. Calculate your average score and determine whether your fatigue is clinically significant.
For each of the following 9 statements, select a number from 1 to 7 that indicates how much you agree with the statement, where 1 = Strongly Disagree and 7 = Strongly Agree.
A 32-year-old healthy individual rates the 9 questions as: 2, 1, 3, 2, 2, 1, 3, 2, 2.
Total Score: 18
Average Score: 2.0
This score is well below 4.0, indicating that fatigue is not a clinically significant issue for this individual.
A 45-year-old reports: 4, 3, 5, 4, 3, 4, 5, 3, 4.
Total Score: 35
Average Score: 3.9
At 3.9, this is just below the 4.0 threshold. The individual should monitor their fatigue levels and discuss with a healthcare provider if symptoms persist or worsen.
A 55-year-old with multiple sclerosis rates: 6, 5, 6, 7, 5, 6, 7, 5, 6.
Total Score: 53
Average Score: 5.9
An average score of 5.9 is well above the 4.0 threshold, indicating clinically significant fatigue that warrants medical evaluation and management.
A 62-year-old with chronic fatigue syndrome rates: 7, 7, 6, 7, 7, 6, 7, 7, 6.
Total Score: 60
Average Score: 6.7
This indicates severe, debilitating fatigue that significantly impacts daily functioning. Comprehensive medical evaluation and management are essential.
The Fatigue Severity Scale (FSS) is a validated 9-item questionnaire developed by Krupp et al. (1989) to assess the severity of fatigue and its impact on daily functioning. It is one of the most widely used fatigue assessment tools in clinical research and practice, particularly for conditions like multiple sclerosis, systemic lupus erythematosus, chronic fatigue syndrome, and Parkinson's disease.
| Average Score | Interpretation |
|---|---|
| < 4.0 | Below clinical threshold โ fatigue is not considered clinically significant |
| 4.0 โ 4.9 | Mild clinically significant fatigue โ may benefit from evaluation and management |
| 5.0 โ 5.9 | Moderate clinically significant fatigue โ medical evaluation recommended |
| 6.0 โ 7.0 | Severe fatigue โ comprehensive medical evaluation and intervention warranted |
The FSS asks respondents to rate their level of agreement with the following statements about fatigue during the past week:
The FSS has been extensively validated in multiple populations including multiple sclerosis, lupus, chronic fatigue syndrome, and Parkinson's disease. It has high internal consistency (Cronbach's ฮฑ > 0.80).
A cutoff score of 4.0 or higher is the most commonly used threshold for clinically significant fatigue. However, some studies use 4.5 or 5.0 depending on the population.
The FSS is a screening and monitoring tool, not a diagnostic instrument. It measures fatigue severity but does not identify the underlying cause of fatigue.
The FSS is useful for monitoring changes in fatigue over time, such as in response to treatment or lifestyle interventions. A change of 0.5โ1.0 points is considered clinically meaningful.
The Fatigue Severity Scale (FSS) is a 9-item self-report questionnaire designed to assess the severity of fatigue and its impact on daily functioning. Developed by Lauren Krupp and colleagues in 1989, the FSS has become one of the most widely used fatigue assessment tools in both clinical practice and research settings.
Fatigue is a common and often debilitating symptom in many medical conditions, including multiple sclerosis (MS), systemic lupus erythematosus (SLE), chronic fatigue syndrome (CFS/ME), Parkinson's disease, rheumatoid arthritis, and post-cancer treatment. Unlike simple tiredness that resolves with rest, pathological fatigue is persistent, disproportionate to activity levels, and significantly interferes with quality of life, work productivity, and social functioning.
The FSS asks respondents to rate their agreement with 9 statements about fatigue over the past week, using a 7-point Likert scale from 1 (strongly disagree) to 7 (strongly agree). The average score provides a quantitative measure of fatigue severity, with a cutoff of 4.0 or higher generally indicating clinically significant fatigue that warrants further evaluation and management.
Your FSS average score falls into one of four categories. A score below 4.0 suggests that fatigue is not currently a clinically significant issue for you. Scores of 4.0 and above indicate clinically significant fatigue of varying severity โ mild (4.0โ4.9), moderate (5.0โ5.9), or severe (6.0โ7.0). Higher scores indicate greater impact of fatigue on daily functioning and quality of life.
It's important to note that the FSS measures fatigue severity but does not diagnose the underlying cause. Many medical conditions, medications, sleep disorders, mental health conditions, and lifestyle factors can contribute to fatigue. Your FSS score should be interpreted in the context of your overall health and discussed with a healthcare provider.
Fatigue is one of the most common and disabling symptoms reported by patients with chronic medical conditions. Despite its prevalence, fatigue is often under-recognized and under-treated in clinical settings. Systematic assessment using validated tools like the FSS helps bridge this gap by providing objective, quantifiable data about fatigue severity.
Regular FSS assessments help healthcare providers track fatigue over time, evaluate treatment effectiveness, and make informed decisions about interventions.
Understanding the severity and impact of fatigue guides treatment decisions, including pharmacological interventions, rehabilitation strategies, and lifestyle modifications.
The FSS is widely used in clinical research as a primary or secondary outcome measure in studies of fatigue interventions across various medical conditions.
Completing the FSS can help individuals better understand their fatigue patterns and recognize when fatigue warrants professional attention.
โ ๏ธ Important Medical Disclaimer: This Fatigue Severity Scale (FSS) Calculator is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. The FSS is a screening tool and does not diagnose any medical condition. Always consult a qualified healthcare provider with any questions about your fatigue or overall health. Do not change your medications or treatment plan based solely on the results from this calculator. If you are experiencing severe, persistent, or worsening fatigue, or if fatigue is accompanied by other concerning symptoms, seek medical evaluation promptly.