Detailed interviews of 40 fibromyalgia patients from three countries (United States, Germany and France) reveal that fatigue is the second most bothersome symptom after pain.*

The investigation was fueled by previous studies involving patient feedback that implied fatigue was a symptom that deserved to be assessed in treatment trials. Currently, the success of a therapy primarily hinges on how well it reduces fibromyalgia pain, with little or no attention paid to fatigue. In addition, there is no clear understanding of the key features of fatigue that need to be measured.

During their interviews, patients were asked open-ended questions, such as, “Tell me about your experience of having fibromyalgia.” So, the goal of the interviews was not to specifically inquire about fatigue, because the investigators wanted to hear what patients had to say spontaneously about their symptoms.

The average duration of fibromyalgia symptoms for the 40 participants was 6.6 years, their average age was 49, and 70% of them were female. When asked about their experience with fibromyalgia, they reported the following symptoms, without prompting:

• pain (78%)
• fatigue (43%)
• sleeping difficulties (18%)
• mobility problems (10%)

Remember, this was based on their unsolicited comments about fibromyalgia. When asked to rate the top three symptoms, the order was basically the same but the percentages were much higher.

“Fibromyalgia fatigue was described as an overwhelming feeling of tiredness that was not relieved by sleep or rest and is often not in proportion to the effort exerted (i.e., participants described becoming tired after doing very little),” state the authors. The participants also made it clear that their fibromyalgia-related fatigue was not just “normal tiredness.”

The participants further described their fatigue in the following eight categories that many of you can probably related to:

• Overwhelming feeling of tiredness (43%) – sometimes to the point that they were unable to do anything
• Not relieved by resting or sleeping (38%) – the fatigue persisted even after what the patient felt was a good night’s sleep
• Not proportional to effort exerted (63%) – it doesn’t take much at all to trigger this symptom
• Feeling of weakness or heaviness (28%) – body feels heavy, weak, or lacks any strength
• Difficult to get motivated (83%) – it takes a large amount of effort to do things, such as just getting out of bed and “getting going” in the morning
• Difficulty doing the things they want to do (60%) – the fatigue/tiredness makes it difficult to do what they want or need to get done
• Having to do things more slowly (38%) – it takes longer to get things done and some patients felt it was related to the feeling of heaviness or weakness
• Difficulty to concentrate, think, or remember things (68%) – fatigue/tiredness affects ability to concentrate, difficulty remembering things, trouble thinking clearly or staying focused

“Men and women described the fatigue experience and its impact in much the same way,” write the authors. Summing up their findings, in fibromyalgia, “fatigue appears to be the second most important symptom and one that has considerable impact on patients’ lives.” Because there are so many diverse fibromyalgia-related fatigue symptoms, however, it will be a challenge to assess the impact of this symptom in treatment trials. But the results from this study may lead to better tools to accurately measure “fatigue” in fibromyalgia patients.

* Humphrey L, et al. BMC Musculoskeletal Disorders 11:216, September 2010.