Curriculum · Metabolic and Endocrine and Diabetes Mellitus
Graves disease and the place of surgery
What it is
Graves disease is one of the causes of thyrotoxicosis with a high 24-hour radioactive iodine uptake, together with multinodular goiter and toxic adenoma; the low uptake group is factitious hyperthyroidism, subacute thyroiditis, ectopic secretion of thyroid hormones, iodine-induced hyperthyroidism and deposits of functioning thyroid cancer metastases. Exophthalmos, that is proptosis, is most likely Graves disease, and pretibial myxedema is seen in Graves disease.
How it presents
Exophthalmos, or proptosis, and pretibial myxedema are the two signs that name it. In a patient with thyroid swelling the eyes are inspected as part of the examination, and auscultation for a bruit shows the increased vascularity and hyperdynamic circulation of hyperthyroidism. The thyroid function symptoms taken in the history are heat or cold intolerance, palpitations, weight or appetite changes, behavioural changes such as irritability, restlessness or depression, and constipation or diarrhoea.
How it is diagnosed
In a goiter, TSH is measured first. A low TSH leads to free T4 and total T3, and a raised free T4 is overt hyperthyroidism, that is a toxic goiter. The etiology is then determined among Graves disease, multinodular goiter with autonomy and painless thyroiditis, by measuring TRAb and by obtaining a thyroid uptake and scan, or a thyroid ultrasound that also looks at thyroid vascularity. A high 24-hour radioactive iodine uptake belongs to Graves disease.