Pain occurs in a wide range of forms in ME/CFS. These include abdominal pain, allodynia, arthralgia, carpal tunnel syndrome, chest pain, chronic pain, ear pain, esophageal spasms, eye pain, fibromyalgia, gallbladder pain, headache, heartburn, migraine, muscle spasms, myalgia, neck pain, proctalgia fugax, sciatica, sinus headaches, vein pain and tenesmus.
- 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."