Myalgia

Prevalence

 * 87.1% - 90.1% of the 2073 patients in a Belgian study of 2001 reported myalgia.
 * Katrina Berne reports a prevalence of 65-95% for muscle and/or joint pain, neck pain.

Symptom recognition

 * In the Canadian Consensus Criteria, pain is a required criteria for diagnosis. It requires that "there is a significant degree of myalgia. Pain can be experienced in the muscles, and/or joints, and is often widespread and migratory in nature. Often there are significant headaches of new type, pattern or severity."
 * In the Fukuda criteria, the symptom of muscle pain can be used to help form a diagnosis.
 * In the Holmes criteria, muscle discomfort or myalgia is an optional criteria for diagnosis, under the section Minor Symptom Criteria.