A subset of interstitial cystitis (IC) patients also have fibromyalgia (FM), a chronic pain disorder with a multitude of symptoms. Although 80 to 90 percent of those affected are women, men and children can have fibromylagia, too. The cause of FM is not known, but many researchers believe that FM is the result of abnormal pain processing resulting from “central sensitization.”

The theory is that chronic pain actually changes the brain’s sensitivity to pain, making people feel pain from stimuli that would not normally be painful. FM patients seem to have changes in nerve-signaling chemicals and nervous system-related hormones.There is also a sensory hypersensitivity which not only causes a greater sensitivity to pain but higher levels of sensitivity to light, noise, and smell. (Research has found that IC patients are “super tasters.” Perhaps the enhanced taste buds relate to the hypersensitivity of smell?)

A number of scientific studies have shown that FM patients have abnormal blood flow to the thalamus region of the brain, abnormalities in the hypothalamic-pituitary-adrenal axis (the “fight or flight” system), low levels of serotonin and tryptophan, and abnormalities in immune system signaling. Recent studies also show that some people may have a genetic predisposition to FM.

For the latest information about FM, visit the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) website.

Revised Wednesday, March 25th, 2015