An invisible illness is an umbrella term for any medical condition that isn’t easily visible to others. Examples include chronic fatigue syndrome, lupus, mental illness, Crohn’s disease and fibromyalgia.
Fibromyalgia is a long term (chronic) condition that causes widespread pain in the muscles, tendons and ligaments all over the body. Despite the fact that it is a painful disease, it is not inflammatory or degenerative. Long term studies suggest that it is not progressive and does not cause permanent damage to the muscles, bones, joints or organs.