New American Thyroid Association guidelines on hyperthyroidism The American Thyroid Association (ATA) has issued new guidelines for diagnosis and management of hyperthyroidism and other causes of thyrotoxicosis. Published online August 17, 2016 in the journal Thyroid, these guidelines include 124 evidence-based recommendations. Some recommendations are as below: • “Hyperthyroidism” has been defined as a form of thyrotoxicosis due to inappropriately high synthesis and secretion of thyroid hormones by the thyroid gland. And, “thyrotoxicosis" is a clinical state resulting from inappropriately high thyroid-hormone action in tissues generally due to inappropriately high tissue thyroid hormone levels. • Serum TSH is recommended as an initial screening test. When thyrotoxicosis is strongly suspected, diagnostic accuracy improves when a serum TSH, free T4 and total T3 are assessed at the initial evaluation. • Medical therapy of any comorbid conditions should be optimized prior to radioactive iodine (RAI) therapy. • Free T4, total T3, and TSH should be measured on follow-up within the first 1–2 months after RAI therapy for Graves’ disease and should be repeated at 4–6 week intervals for 6 months, or until the patient becomes hypothyroid and is stable on thyroid hormone replacement. • Methimazole is the drug of choice for Graves’ disease, except during the first trimester of pregnancy (propylthiouracil is preferred), thyroid storm, and in patients with minor reactions to methimazole who do not opt for RAI or surgery. • All patients should be informed about the adverse effects of antithyroid drugs, preferably in writing. • Patients on antithyroid drugs should get a differential white blood cell count done during febrile illness and at the onset of pharyngitis. • Thyroid receptor antibodies (TRAb) should be measured to guide treatment decisions for e.g. whether stop or continue with the antithyroid drugs; normal levels indicate greater chance for remission. • In pregnant women, TRAb level should be measured first during the first trimester and, if elevated, again at 18–22 weeks of gestation. If the level is still high, the fetus or neonate should be evaluated for thyroid dysfunction after birth. • Near-total or total thyroidectomy is the procedure of choice for Graves’ disease. The surgery should preferably done by a high-volume thyroid surgeon.