Fatigue Severity Scale Assessment
The FSS measures how severely fatigue affects your daily life. Nine statements rated 1-7 produce a mean score. ≥4.0 indicates clinically significant fatigue.
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Mean ≥4.0 = clinically significant Used in MS, lupus, CFS, fibromyalgia Validated since 1989 (Krupp et al.)
Ready to run the numbers?
Why: Fatigue is a common symptom in MS, lupus, CFS, fibromyalgia, and depression. The FSS helps quantify its impact.
How: Rate each of 9 statements 1-7. The mean score indicates severity. Higher scores mean greater fatigue impact.
Run the calculator when you are ready.
🧠 Multiple Sclerosis Patient
MS patient with typical fatigue pattern - high impact on function
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😴 Chronic Fatigue Syndrome
CFS/ME patient with severe, pervasive fatigue across all domains
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✅ Normal Fatigue Levels
Healthy individual with typical fatigue responses
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🦋 Lupus Patient
SLE patient with fatigue as prominent symptom
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💜 Fibromyalgia Patient
Fibromyalgia with fatigue alongside chronic pain
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Sample Clinical Scenarios
🧠 Multiple Sclerosis Patient
MS patient with typical fatigue pattern - high impact on function
Click to load
😴 Chronic Fatigue Syndrome
CFS/ME patient with severe, pervasive fatigue across all domains
Click to load
✅ Normal Fatigue Levels
Healthy individual with typical fatigue responses
Click to load
🦋 Lupus Patient
SLE patient with fatigue as prominent symptom
Click to load
💜 Fibromyalgia Patient
Fibromyalgia with fatigue alongside chronic pain
Click to load
Fatigue Severity Scale Questions
Rate how much you agree with each statement based on your experience over the past week.
Patient Information (Optional)
FSS Results
Mean Score
out of 7
Category
Clinical Significance
Total Score
Fatigue Profile
Impact Profile
Item Scores
Recommendations
Clinically significant fatigue - consider medical evaluation
Screen for underlying conditions (thyroid, anemia, sleep disorders)
Implement energy conservation strategies
Consider cognitive behavioral therapy for fatigue
Conditions to Consider
Hypothyroidism
Anemia (iron deficiency, B12, folate)
Sleep disorders (apnea, insomnia)
Depression/anxiety
Chronic fatigue syndrome (CFS/ME)
Autoimmune conditions
Medication side effects
Chronic infections
Calculation Details
Q1: 4/7 - "My motivation is lower when I am fatigued..."
Q2: 4/7 - "Exercise brings on my fatigue..."
Q3: 4/7 - "I am easily fatigued..."
Q4: 4/7 - "Fatigue interferes with my physical functioning..."
Q5: 4/7 - "Fatigue causes frequent problems for me..."
Q6: 4/7 - "My fatigue prevents sustained physical functioning..."
Q7: 4/7 - "Fatigue interferes with carrying out certain dutie..."
Q8: 4/7 - "Fatigue is among my three most disabling symptoms..."
Q9: 4/7 - "Fatigue interferes with my work, family, or social..."
Total Score: 4 + 4 + 4 + 4 + 4 + 4 + 4 + 4 + 4 = 36
Mean Score: 36 ÷ 9 = 4.00
Category: Moderate Fatigue (4.0-4.9)
Clinical Significance: Yes - Score ≥4.0 indicates significant fatigue
Further evaluation recommended
For informational purposes only — not medical advice. Consult a healthcare professional before acting on results.
🏥 Health Facts
FSS mean ≥4.0 indicates clinically significant fatigue
— Krupp 1989
9 items, each scored 1-7. Total range 9-63.
— FSS
What is the Fatigue Severity Scale?
The Fatigue Severity Scale (FSS) is a validated self-report questionnaire that measures the severity of fatigue and its effect on daily activities. Developed by Krupp et al. in 1989, it consists of 9 statements rated on a 7-point scale, with higher scores indicating more severe fatigue impact.
Validated Tool
Extensively validated in multiple conditions including MS, lupus, CFS, and depression.
Quick Assessment
9 simple questions that can be completed in under 5 minutes.
Clinical Threshold
Clear cutoff score (≥4) to identify clinically significant fatigue.
How Does the FSS Work?
Scoring System
Response Scale
- 1 = Strongly Disagree
- 2-3 = Disagree/Somewhat Disagree
- 4 = Neutral
- 5-6 = Somewhat Agree/Agree
- 7 = Strongly Agree
Score Interpretation
When to Use the FSS
Common Conditions
- • Multiple Sclerosis (MS)
- • Chronic Fatigue Syndrome (CFS/ME)
- • Systemic Lupus Erythematosus
- • Fibromyalgia
- • Depression
- • Parkinson's Disease
Clinical Uses
- • Initial fatigue assessment
- • Tracking treatment response
- • Research outcome measure
- • Disability evaluation
- • Quality of life assessment
FSS Scoring Formula
Mean Score Calculation
Range: 1.0 to 7.0
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