Graves disease is the most common cause of an overactive thyroid gland (hyperthyroidism). It is caused by an antibody that acts like thyroid-stimulating hormone (TSH) and causes the thyroid gland to produce excess thyroid hormones (thyroxine (T4) and tri-idothyronine (T3)). This antibody has been given a variety of names and abbreviations including: TSH-receptor antibodies (TRAbs or TSH-Rabs), Thyroid Stimulating Immunoglobulins (TSI), Thyroid Binding Inhibiting Immunoglobulins (TBII) and Long Acting Thyroid Stimulator (LATS).
Women over 20 years of age are most likely to have Graves disease. Those with the disease may have protruding eyes, weight loss, increased appetite, nervousness and may have an increased heart rate and an enlarged thyroid gland (goitre) seen in the neck.