Grave's disease, also called toxic diffuse goiter, is an autoimmune disorder, meaning the body's immune system attacks its own healthy cells. In Grave's disease, the immune system makes antibodies that attach to thyroid cells and cause the thyroid to make too much thyroid hormone. Grave's disease is most common in women over age 20.However the disorder may occur at any age and may affect men as well.
Attribution: Straight Talk Foundation