What is the Fatigue Severity Scale (FSS)?

The Fatigue Severity Scale (FSS) is a 9-item self-report questionnaire that measures the severity of fatigue.

Who developed the FSS and when?

Developed by Krupp, LaRocca, Muir-Nash, & Steinberg in 1989.

What type of assessment is the FSS?

It is a self-report questionnaire using a 7-point Likert scale.

What does the FSS assess?

• Severity of fatigue symptoms
• Impact of fatigue on motivation
• Effect on exercise and physical activity
• Interference with daily activities
• Social and work functioning

How many items and what format?

9 items, rated 1-7 (1=Strongly disagree, 7=Strongly agree).

How is the FSS scored?

Mean score of all items; higher scores indicate more severe fatigue.

Are there versions of the FSS?

Standard 9-item; translated into multiple languages.

Who can use the FSS?

Adults with fatigue-related conditions; widely used in research and clinical practice.

What are the strengths of the FSS?

Quick, reliable, validated for various fatigue conditions.

What are the limitations of the FSS?

Subjective; may not distinguish between fatigue types.

How is the FSS used?

Clinical assessment, treatment monitoring, research.