Fibromyalgia (FM) or fibromyalgia syndrome (FMS) is a chronic pain disorder. Symptoms include widespread or localized muscle and joint pain, stiffness, swelling, and tenderness. Most people with fibromyalgia experience fatigue, sleep disturbances, headache, anxiety, and memory problems. Some also report high sensitivity to noises, lights, smells, and temperature changes.

Female sufferers of fibromyalgia outnumber males by about 9 to 1. It is the second most common illness presented to rheumatologists, led only by arthritis. Researchers estimate that 75 percent of fibromyalgia cases go unreported. [ Mayo Clinic Proceedings, 2011 ]

Fibromyalgia has no known cause. Researchers have observed abnormalities of central nervous system processes and imbalances of brain chemicals and growth hormone. People with fibromyalgia may have three times the normal concentration of Substance P, a spinal fluid chemical that amplifies pain signals. Many patients attribute the onset of fibromyalgia to a particular injury, illness, or traumatic event. The condition does not progress and does not damage bones, joints, or tissues.

Hyperbaric oxygen therapy (HBOT) has been shown to reduce the pain and tenderness associated with fibromyalgia and other chronic pain disorders. Some researchers believe HBOT also changes brain function associated with chronic pain conditions.