Plummer disease, also called toxic multinodular goitre, thyroid condition characterized by marked enlargement of the thyroid gland, thyroid nodules, and overproduction of thyroid hormone (hyperthyroidism). Plummer disease occurs in older people and is of unknown etiology. Its symptoms resemble those of hyperthyroidism with swelling of the thyroid gland. Hyperthyroidism more likely occurres in adults than in children. There is a silent hyperthyroidism which happens after pregnancy. Long story short: It is a common cause of hyperthyroidism in which there is excess production of thyroid hormones from functionally autonomous thyroid nodules, which do not require stimulation from thyroid stimulating hormone