Pain

Pain in medical diagnosis is regarded as a symptom of an underlying condition.

Pain in ME/CFS
Pain occurs in a wide range of forms in ME/CFS and is typically chronic. These include:
 * abdominal pain
 * aching pain
 * arthralgia (joint pain)
 * chest pain
 * eye pain associated with cervical muscle tension
 * flu-like pain and discomfort
 * headaches including sinus headaches, tension-type headaches and migraines
 * generalized hyperalgesia
 * lymph node tenderness
 * lowered pain threshold or chronic, widespread allodynia
 * muscle spasms
 * muscle-tendon junction pain
 * myalgia (muscle pain)
 * myofascial pain
 * nerve pain (neuropathic pain) including burning pain, shooting pain and stabbing pains
 * pins and needles
 * positive fibromyalgia tender points occur in most people with ME/CFS
 * peripheral neuropathies
 * radiating pain
 * sore throat
 * pain is typically widespread, migratory, and fluctuates

Pain can also occur as a consequence of commonly comorbid illnesses such as migraine, myofascial pain syndrome (MPS), temporomandibular joint syndrome (TMJ), interstitial cystitis, Raynaud's phenomenon, IBS, or from fibromyalgia, which is considered an overlapping syndrome.

Pain in fibromyalgia
Researchers believe that fibromyalgia (FM) amplifies painful sensations by affecting the way your brain processes pain signals.

Pain in fibromyalgia is commonly referred to as chronic widespread pain (CWP). Types of pain commonly reported in fibromyalgia include:
 * allodynia
 * joint pain, which may be worsened by weight gain causing stress on joints
 * hyperalgesia
 * muscle spasms
 * myalgia (muscle pain)
 * nerve pain (neuropathic pain)

Many people with fibromyalgia will have other pain conditions such as:
 * tension headaches and migraines
 * temporomandibular joint disorders (TMJ)
 * rheumatoid arthritis (RA)
 * lupus
 * Sjögren's syndrome
 * ankylosing spondylitis
 * irritable bowel syndrome (IBS)
 * menstrual cycle cramps and interstitial cystitis 

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."

Pain is an optional neurological criteria in the International Consensus Criteria, with many different types of pain recognized.

The older Fukuda criteria for chronic fatigue syndrome (1994) recognized sore throat, tender cervical or axillary lymp nodes, headaches and other types of pain but did not require them for diagnosis.

Recording pain
The primer for the International Consensus Criteria for ME includes a pain chart and the visual-analogue pain scale.