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Autoimmune thyroiditis; Hashimoto's thyroiditis
About 15 million Americans have unrecognized thyroid disease, mostly subclinical hypothyroidism (mildly underactive thyroid). Less than 2% of the U.S. population has full-blown hypothyroidism.
Women. Women have 10 times the risk of hypothyroidism as men, with the difference being significant after age 34. Because the symptoms of hypothyroidism and menopause are so similar, hypothyroidism may easily be missed.
Pregnancy is a major factor in the higher risk in women. It affects the thyroid in a number of ways and poses a high risk for hypothyroidism, both during pregnancy and afterward. For one, iodine requirements are high in both the mother and the fetus. Changes in reproductive hormones also cause changes in thyroid hormone levels. In addition, some women develop antibodies to their own thyroid during pregnancy, causing a condition known as postpartum autoimmune, or subacute, thyroiditis. This occurs in up to 10% of pregnant women and tends to develop 4 - 12 months after delivery. It is a limited condition and nearly always clears up. However, it does pose a risk for the development of permanent hypothyroidism later on.
Age. The risk for hypothyroidism is greatest after age 50 and increases with age. However, hypothyroidism can affect people of all ages.
Genetics plays a role in many cases of underactive and overactive thyroid. The genetics involved with hypothyroidism are complicated, however. Certain genetic features, for example, appear to play a role in Hashimoto's thyroiditis and postpartum thyroiditis in Caucasians, but others affect different ethnic groups. Thyroid disease will often skip generations. For example, someone with an underactive thyroid may have healthy parents but have grandparents who had thyroid troubles. Some people inherit a tendency for thyroid problems but never become ill, while others become very sick.
Smoking significantly increases risk for thyroid disease, particularly autoimmune Hashimoto's thyroiditis and postpartum thyroiditis. Smoking also increases the negative effects of hypothyroidism, notably on the arteries and heart.
People with certain medical conditions have a higher risk for hypothyroidism. These conditions include:
Many drugs affect the thyroid, so anyone being treated for a chronic disease, taking thyroid medication, and those at risk for a thyroid disorder should discuss the impact these drugs may have on their thyroid.
Abalovich M, Amino N, Barbour LA, Cobin RH, De Groot LJ, Glinoer D, et al. Management of thyroid dysfunction during pregnancy and postpartum: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2007 Aug;92(8 Suppl):S1-47.
Allahabadia A, Razvi S, Abraham P, Franklyn J. Diagnosis and treatment of primary hypothyroidism. BMJ. 2009 Mar 26;338:b725. doi: 10.1136/bmj.b725.
American Academy of Pediatrics, Rose SR; Section on Endocrinology and Committee on Genetics, American Thyroid Association, Brown RS; Public Health Committee, et al. Update of newborn screening and therapy for congenital hypothyroidism. Pediatrics. 2006 Jun;117(6):2290-303.
Brent GA, Larsen PR, Davies TF. Hypothyroidism and thyroiditis. In: Kronenberg: HM, Shlomo M, Polonsky KR, Larsen PR, eds. Williams Textbook of Endocrinology. 11th ed. Philadelphia, Pa: Saunders Elsevier; 2008:chap 12.
Fatourechi V. Subclinical hypothyroidism: an update for primary care physicians. Mayo Clin Proc. 2009;84(1):65-71.
Gyamfi C, Wapner RJ, D'Alton ME. Thyroid dysfunction in pregnancy: the basic science and clinical evidence surrounding the controversy in management. Obstet Gynecol. 2009 Mar;113(3):702-7.
Kliegman RM. Hypothyroidism. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 566.
Mestman JH. Thyroid and parathyroid diseases in pregnancy. In: Gabbe SG, Niebyl JR, Simpson JL, eds. Obstetrics: Normal and Problem Pregnancies. 5th ed.Philadelphia, Pa: Elsevier Churchill Livingstone; 2007:chap 38.
Ochs N, Auer R, Bauer DC, Nanchen D, Gussekloo J, Cornuz J, Rodondi N. Meta-analysis: subclinical thyroid dysfunction and the risk for coronary heart disease and mortality. Ann Intern Med. 2008 Jun 3;148(11):832-45. Epub 2008 May 19.
Roberts LM, Pattison H, Roalfe A, Franklyn J, Wilson S, Hobbs FD, et al. Is subclinical thyroid dysfunction in the elderly associated with depression or cognitive dysfunction? Ann Intern Med. 2006 Oct 17;145(8):573-81.
Rodondi N, Aujesky D, Vittinghoff E, Cornuz J, Bauer DC. Subclinical hypothyroidism and the risk of coronary heart disease: a meta-analysis. Am J Med. 2006 Jul;119(7):541-51.
Stagnaro-Green A. Maternal thyroid disease and preterm delivery. J Clin Endocrinol Metab. 2009 Jan;94(1):21-5. Epub 2008 Nov 4.
Vaidya B, Pearce SH. Management of hypothyroidism in adults. BMJ. 2008 Jul 28;337:a801. doi: 10.1136/bmj.a801.
Villar HC, Saconato H, Valente O, Atallah AN. Thyroid hormone replacement for subclinical hypothyroidism. Cochrane Database Syst Rev. 2007 Jul 18;(3):CD003419.
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