Fibromyalgia and Arthritis Fibromyalgia is not arthritis, but rather is an arthritis related condition. Fibromyalgia and arthritis occur together in up to 65% of cases. in Public bookmarkswith fibromyalgia_and_arthritisfibromyalgia_arthritis Note: Fibromyalgia is not arthritis, but rather is an arthritis related condition. Fibromyalgia and arthritis occur together in up to 65% of cases.