Has the cause of fibromyalgia finally been discovered? Newshub 12 hrs ago What to watch next Replay Video UP NEXT The cause of a mysterious illness that affects millions of people, yet has struggled to be recognised as real, might finally have been discovered. People with fibromyalgia syndrome (FMS or simply fibromyalgia) experience a heightened response to physical stimuli and pain. It affects somewhere between 2 to 8 percent of the population, previous research has found, but it's difficult to diagnose because there aren't any obvious observable physical symptoms, nor does it damage tissue. There have been numerous different treatments tried but with only limited success, since no one's been sure what's behind it - the most common explanation being that patients' brains process pain abnormally.