Pain is the most prominent symptom of fibromyalgia. Originally it was thought to be a disease of the muscles and tissues because that's where the pain is usually felt most. In fact, that's how it got its name. "Fibro" refers to fibrous tissues and "myalgia" means pain, so the name fibromyalgia literally means "pain in fibrous tissues."
However, research for the past few years has begun to reveal that, although pain may be felt in the muscles, the problem actually originates in the central nervous system (CNS). There is a malfunction in the CNS, which causes abnormal pain processing. The result is pain amplification. Something that would cause little to no pain in a healthy person can be extremely painful to someone with fibromyalgia. For example, what feels like a nice firm handshake to the average person can make the person with FM feel as if their hand is being crushed.
The pain of FM is chronic and widespread. It affects all four quadrants of the body (right and left sides, above and below waist), although not necessarily all at the same time. Its intensity may range from mild to profound. FM pain tends to migrate, sometimes affecting one part of the body and sometimes another. Patients also report that their bodies ache all over, much like having the flu. In addition to the aching, FM pain has been described by different people as burning, throbbing, sharp, stabbing or shooting pain. Most people with FM also complain of feeling stiff and achy when they first get up in the morning.