Hi teresa Fibromyalgia affects the joints and muscles. Like your knees elbows, neck, back ect.. It cause fatigue achiness, stiffness. Its sorta like having the flu but it never goes away. Go to Medline health, go to diseases and look under fibromyalagia and it will tell you. I wish i knew how to cut and paste but i hae'nt learned that yet. hope that helps a little. Colette