Chapter 30 Hyperthyroidism
INTRODUCTION
Description: Hyperthyroidism is excess production of thyroid hormone. Hyperthyroidism is three times more common in women and may result in menstrual irregularity or fertility disturbances, or it may complicate pregnancy. It may occur because of Graves’ autoimmune disease (most common) or toxic single or multinodular goiters. Rarely, trophoblastic tumors or dermoid cysts may be the cause.
ETIOLOGY AND PATHOGENESIS
Causes: Graves’ disease—an autoimmune disease in which thyroid-stimulating immunoglobulins bind to thyroid-stimulating hormone (TSH) receptors mimicking the action of thyroid-stimulating hormone and causing excess secretion of triiodothyronine (T3) and thyroxine (T4). Goiter and exophthalmos are common. Toxic single or multinodular goiter—one or more autonomous benign nodules that slowly grow. Exophthalmos and myxedema are generally absent.
