Graves disease is a type of autoimmune disease which results in the hyperactivity of the thyroid gland, also known as hyperthyroidism. The thyroid gland becomes overactive and starts producing excessive amounts of the thyroid hormone. It is one of the most common causes of hyperthyroidism and is referred to as toxic diffuse goiter. This disease generally affects people in their early adolescent years and may be hereditary in nature. Graves disease can affect almost anyone but is rarely a life threatening disorder. Studies show that this disorder is more common in women below the age of 40 years.