This refers to the surplus production of a hormone (thyroxine) by the butterfly-shaped gland in the neck (thyroid). Hyperthyroidism is a condition in which an overactive thyroid gland is producing an excessive amount of thyroid hormones that circulate in the blood. (“Hyper” means “over” in Greek). Thyroid hormones include thyroxine (T4) and triiodothyronine (T3). T3 is actually the most active thyroid hormone. Much of the T4 is converted to T3 in the bloodstream. Hyperthyroidism can increase metabolism and as such,it is also called the OVERACTIVE THYROID.Normally, the rate of thyroid hormone production is controlled by the brain from the pituitary gland, which is in turn regulated by the hypothalamus.
Statistic shows that in more than 70% of cases, hyperthyroidism is caused by Graves’ disease and can be associated with eye disease (Graves’ opthalmopathy).Normally, the immune system helps protect your body against viruses, bacteria, and other substances. An autoimmune disease causes it to attack your body’s tissues and/or organs. With Graves’ disease, the immune system stimulates your thyroid, making it produce too much hormone. Doctors think Graves’ disease may run in families. It is most common among young women.