Fibromyalgia syndrome affects the muscles and soft tissue. Fibromyalgia, also called fibromyalgia syndrome (FMS), is a long-term condition that causes pain all over the body.

The exact cause of fibromyalgia is unknown, but it’s thought to be related to abnormal levels of certain chemicals in the brain and changes in the way the central nervous system (brain, spinal cord and nerves) processes pain messages carried around the body.

It’s also suggested that some people are more likely to develop fibromyalgia because of genes inherited from their parents.