CLINICAL FINDINGS, DIAGNOSIS AND DRUG-THE RAPY OF HYPERTHYROIDISM

Graves' disease and toxic uni- or multinodular goiter are the most fre quent causes of hyperthyroidism. Graves' disease is caused by thyroid stimulating immunoglobulins which are directed against the TSH recepto r of thyroid follicular cells. Graves' disease affects more females th an males and is associated with diffuse goiter and a rapid appearance of symptoms and signs of hyperthyroidism. Patients with Graves' diseas e are on average younger than patients with toxic nodular goiter. The diagnosis of Graves' disease is usually easy, particularly if signs of endocrine opthalmopathy are present. Toxic nodular goiter is seen mor e often in older patients with pre-existing goiters. Symptoms and sign s of hyperthyroidism often appear only slowly. Hyperthyroidism in thes e older patients can be oligosymptomatic. Older patients should theref ore be investigated for the presence of hyperthyroidism, even if they present only a few symptoms or signs which could suggest this diagnosi s. The development of ultrasensitive TSH assays has simplified the dia gnosis of hyperthyroidism and made the TRH-test, often used in the pas t, almost superfluous. At the present time, it is practically always p ossible to differentiate between Graves' disease and toxic nodular goi ter as the cause of hyperthyroidism on the basis of clinical and labor atory findings alone, and in many cases thyroid scintiscans are theref ore no longer necessary. A patient with newly diagnosed Graves' diseas e is treated with antithyroid drugs (carbimazole or PTU) for one year. If hyperthyroidism persists after this one year of antithyroid drug t reatment, or if it recurs, another year of therapy with carbimazole or PTU is indicated. Graves' hyperthyroidism which continues after the s econd year of antithyroid drug treatment is treated with radioiodine o r surgery. Toxic nodular goiters are treated surgically or with radioi odine. Antithyroid drugs are usually only used to induce euthyroidism in patients who are to be thyroidectomized, since thyroidectomy in a h yperthyroid patient carries with it the risk of thyroid storm induced by the thyroid operation.