Over secretion of thyroxin leads to symptoms that include fast heartbeat, rapid breathing as well as a protrusion of the eyes and swelling of the neck. This is known as exophthalmic goitre.
Exophthalmic goitre is a form of hyperthyroidism that affects the eyes. It is a type of autoimmune disease that is usually found in children. The thyroid gland becomes overactive and secretes an excessive amount of thyroid hormones in this state.