What is Exophthalmic goiter? How it is caused? Write its symptoms

Exophthalmic goitre, also called Grave’s disease : It is an endocrine disorder that is the most common cause of hyperthyroidism. In Grave’s disease excessive secretion of thyroxine hormone is accompanied by diffuse enlargement of the thyroid glands.
It is an autoimmune disease where patients produce antibodies that act on the thyroid glands to increase thyroxine hormone production and thyroid size. Patients suffering from cancer of thyroid glands or those with nodules in the thyroid glands suffer from very high levels of thyroid hormones leading to hyperthyroidism.
Such patients show some typical symptoms that include elevated metabolic rate, sweating, rapid and irregular heartbeat, weight loss despite increased appetite, frequent bowel movement and nervousness. Some patients may also experience exophthalmos (or protrusion of the eye balls). Thus this condition is also known as exophthalmic goitre.