Thyrotoxicosis - A review
Background: Thyrotoxicosis is the clinical and biochemical manifestations of exposure of tissues to excessive quantities of thyroid hormones, specifically free thyroxine (T4 ), tri-iodothyronine (T3) or both. The terms “thyrotoxicosis”, “hyperthyroidism” and “Graves\' disease” are used interchangeably because hyperthyroidism due to Graves\' disease is the commonest cause of thyrotoxicosis. Studies in most countries reveal an increasing incidence of thyrotoxicosis. Aim: To present an update on the causes and management of thyrotoxicosis with emphasis on Graves\' disease. Methods: A review of publications obtained from medline search and Google on “thyrotoxicosis” or “Graves\' disease” or “hyperthyroidism” was done. Results: Graves\' disease constitutes about 70% of cases of thyrotoxicosis.The common clinical features include weight loss despite enhanced appetite, hyperactivity and heat intolerance etc. Features specific to Graves\' disease include ophthalmopathy, pretibial myxoedema and thyroid acropachy. Thyrotoxicosis affects about 1% of women and 0.1% of men globally. It is indicated in most cases by an elevated serum concentration of total T4 and T3 and a suppressed thyroid stimulating hormone (TSH). Thyroid imaging and radiotracer uptake measurements combined with serological data enable specific aetiological diagnosis. The three treatment modalites for Graves\' disease are antithyroid drugs, 131I therapy and thyroidectomy. Conclusion: The incidence of thyrotoxicosis is increasing globally. Optimal clinical and laboratory evaluation of the patient is necessary to identify the cause and institute appropriate therapy. There is need for prospective studies to identify the factors for the observed increasing incidence of thyrotoxicosis in our population.
Keywords: Thyrotoxicosis, Hyperthyroidism, Graves\' disease, Review
Port Harcourt Medical Journal Vol. 2 (3) 2008: pp. 184-197
Manuscripts published do not necessarily reflect the opinion of the Editorial Board but that of the author(s).