Physical Therapy Toolbox: Fatigue Severity Scale

The Fatigue Severity Scale (FSS) is a method of evaluating fatigue in multiple sclerosis and other conditions including Chronic Fatigue Immune Dysfunction Syndrome (CFIDS) and Systemic Lupus Erythmatosis (SLE).

The Fatigue Severity Scale (FSS) is designed to differentiate fatigue from clinical depression, since both share some of the same symptoms. Essentially, the FSS consists of answering a short questionaire that requires the patient to rate their level of fatigue. The obvious problem with this measure is its subjectivity.

The FSS questionaire contains nine statements that attempt to explore severity of fatigue symptoms. The patient is asked to read each statement and circle a number from 1 to 7, depending on how closely they feel the statement applied to them over the preceding week. A low value indicates that the statement does not describe them, while a high value indicates that the statement does describe them.

The scoring is done by calculating the average response to the questions (adding up all the answers and dividing by nine).
People with depression alone score about 4.5. But people with fatigue related to MS, SLE or CFIDS average about 6.5.

Physical Therapy Toolbox Fatigue Severity Scale [PDF]

Supporting Research



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