How does fibromyalgia differ from arthritis in people?

See below: Fibromyalgia is thought to be a nervous system condition in which pain thresholds are abnormally low which causes widespread muscular pain. It differs from arthritis in that the joints are not typically involved even though people with fibromyalgia might complain of joint pain. There is typically little to no arthritis in people correctly diagnosed with fibromyalgia.

Inflammation: Arthritis is inflammation of the joints, which can be redness, swelling, joint fluid and stiffness. Fibromyalgia is pain, including joint pain, but not usually inflammation. People who have arthritis can have fibromyalgia, making their arthritis pain worse, but most people with fibromyalgia do not have arthritis.