In overt hyperthyroidism, serum levels of free T4 and triiodothyronine (T3) or levels of T3 alone are elevated, and serum thyrotropin (TSH) levels are suppressed. In subclinical hyperthyroidism, levels of free T4 and T3 are normal, thyrotropin levels are suppressed, and thyroid hormone levels are usually in the middle to upper range of normal. Continue reading
Clinical hyperthyroidism, also called thyrotoxicosis, is caused by the effects of excess thyroid hormone and can be triggered by different disorders. Etiologic diagnosis influences prognosis and therapy.