Hyperthyroidism: Difference between revisions

{{Short description|ThyroidClinical glandsyndrome diseasecaused thatby involves an overproduction ofexcessive thyroid hormone}}

| deaths = Rare directly, unless [[thyroid storm]] occurs; associated with increased mortality if untreated (1.23 [[hazard ratio|HR]])<ref name="Lillevang-Johansen Abrahamsen Jørgensen Brix 2017 pp. 2301–2309">{{cite journal | last1=Lillevang-Johansen | first1=Mads | last2=Abrahamsen | first2=Bo | last3=Jørgensen | first3=Henrik Løvendahl | last4=Brix | first4=Thomas Heiberg | last5=Hegedüs | first5=Laszlo | title=Excess Mortality in Treated and Untreated Hyperthyroidism Is Related to Cumulative Periods of Low Serum TSH | journal=The Journal of Clinical Endocrinology & Metabolism | publisher=The Endocrine Society | volume=102 | issue=7 | date=2017-03-28 | issn=0021-972X | doi=10.1210/jc.2017-00166 | pages=2301–2309| pmid=28368540 | s2cid=3806882 | doi-access=free }}</ref>

'''Hyperthyroidism''' is the condition that occurs due to excessive production of [[thyroid hormone]]s by the [[thyroid gland]].<ref name=ATA2011/> '''Thyrotoxicosis''' is the condition that occurs due to excessive thyroid hormone of any cause and therefore includes hyperthyroidism.<ref name=ATA2011>{{cite journal | vauthors = Bahn Chair RS, Burch HB, Cooper DS, Garber JR, Greenlee MC, Klein I, Laurberg P, McDougall IR, Montori VM, Rivkees SA, Ross DS, Sosa JA, Stan MN | display-authors = 6 | title = Hyperthyroidism and other causes of thyrotoxicosis: management guidelines of the American Thyroid Association and American Association of Clinical Endocrinologists | journal = Thyroid | volume = 21 | issue = 6 | pages = 593–646 | date = June 2011 | pmid = 21510801 | doi = 10.1089/thy.2010.0417 }}</ref> Some, however, use the terms interchangeably.<ref>{{cite web| vauthors = Schraga ED |title=Hyperthyroidism, Thyroid Storm, and Graves Disease|website=Medscape|url=http://emedicine.medscape.com/article/767130-overview|access-date=20 April 2015|date=30 May 2014|url-status=live|archive-url=https://web.archive.org/web/20150405111836/http://emedicine.medscape.com/article/767130-overview|archive-date=5 April 2015}}</ref> Signs and symptoms vary between people and may include irritability, muscle weakness, sleeping problems, a [[tachycardia|fast heartbeat]], [[heat intolerance]], [[diarrhea]], [[goiter|enlargement of the thyroid]], hand [[tremor]], and [[weight loss]].<ref name=NIH2012/> Symptoms are typically less severe in the elderly and during [[pregnancy]].<ref name=NIH2012/> An uncommon but life-threatening complication is [[thyroid storm]] in which an event such as an [[infection]] results in worsening symptoms such as confusion and a [[hyperthermia|high temperature]]; this often results in death.<ref name=Clin2014/> The opposite is [[hypothyroidism]], when the thyroid gland does not make enough thyroid hormone.<ref>{{cite web|author1=NIDDK|title=Hypothyroidism|url=http://www.niddk.nih.gov/health-information/health-topics/endocrine/hypothyroidism/Pages/fact-sheet.aspx|access-date=20 April 2015|date=13 March 2013|url-status=live|archive-url=https://web.archive.org/web/20160305010654/http://www.niddk.nih.gov/health-information/health-topics/endocrine/hypothyroidism/Pages/fact-sheet.aspx|archive-date=5 March 2016}}</ref>

Treatment depends partly on the cause and severity of disease.<ref name=NIH2012/> There are three main treatment options: [[radioiodine therapy]], medications, and thyroid surgery.<ref name=NIH2012/> Radioiodine therapy involves taking [[iodine-131]] by mouth which is then concentrated in and destroys the thyroid over weeks to months.<ref name=NIH2012/> The resulting hypothyroidism is treated with synthetic thyroid hormone.<ref name=NIH2012/> Medications such as [[beta blockers]] may control the symptoms, and [[anti-thyroid medication]]s such as [[methimazole]] may temporarily help people while other treatments are having an effect.<ref name=NIH2012/> Surgery to remove the thyroid is another option.<ref name=NIH2012/> This may be used in those with very large thyroids or when cancer is a concern.<ref name=NIH2012/> In the United States hyperthyroidism affects about 1.2% of the population.<ref name=ATA2011/> Worldwide, hyperthyroidism affects 2.5% of adults.<ref name="Lee 2023">{{cite journal |last1=Lee |first1=Sun Y. |last2=Pearce |first2=Elizabeth N. |title=Hyperthyroidism: A Review |journal=JAMA |date=17 October 2023 |volume=330 |issue=15 |pages=14721472–1483 |doi=10.1001/jama.2023.19052|pmid=37847271 |pmc=10873132 |s2cid=265937262 }}</ref> It occurs between two and ten times more often in women.<ref name=NIH2012/> Onset is commonly between 20 and 50 years of age.<ref name=Clin2014/> Overall the disease is more common in those over the age of 60 years.<ref name=NIH2012/>

Major clinical signs of hyperthyroidism include [[weight loss]] (often accompanied by an increased [[appetite]]), anxiety, [[heat intolerance]], hair loss (especially of the outer third of the eyebrows), muscle aches, weakness, fatigue, hyperactivity, irritability, [[hyperglycemia|high blood sugar]],<ref name="Thyrotoxicosis and Hyperthyroidism"/> [[polyuria|excessive urination]], [[polydipsia|excessive thirst]], [[delirium]], [[tremor]], [[pretibial myxedema]] (in [[Graves' disease]]), [[emotional lability]], and sweating. [[Panic attacks]], inability to concentrate, and [[memory]] problems may also occur. [[Psychosis]] and [[paranoia]], common during [[thyroid storm]], are rare with milder hyperthyroidism. Many persons will experience complete remission of symptoms 1 to 2 months after a [[euthyroid]] state is obtained, with a marked reduction in anxiety, sense of exhaustion, irritability, and depression. Some individuals may have an increased rate of anxiety or persistence of [[affective]] and cognitive symptoms for several months to up to 10 years after a euthyroid state is established.<ref>{{cite book|title=Bradley's neurology in clinical practice.|publisher=Elsevier/Saunders|location=Philadelphia, PA|chapter=Depression and Psychosis in Neurological Practice.|year=2012|isbn=978-14377043411-4377-0434-1|pages=102–103|edition=6th}}</ref> In addition, those with hyperthyroidism may present with a variety of physical symptoms such as [[palpitations]] and [[Heart arrhythmia|abnormal heart rhythms]] (the notable ones being [[atrial fibrillation]]), shortness of breath ([[dyspnea]]), loss of [[libido]], [[amenorrhea]], [[nausea]], [[vomiting]], [[diarrhea]], [[gynecomastia]] and [[feminization (biology)|feminization]].<ref>{{cite journal | vauthors = Chan WB, Yeung VT, Chow CC, So WY, Cockram CS | title = Gynaecomastia as a presenting feature of thyrotoxicosis | journal = Postgraduate Medical Journal | volume = 75 | issue = 882 | pages = 229–231 | date = April 1999 | pmid = 10715765 | pmc = 1741202 | doi = 10.1136/pgmj.75.882.229 }}</ref> Long term untreated hyperthyroidism can lead to [[osteoporosis]]. These classical symptoms may not be present often in the elderly.{{Citation needed|date=December 2010}}

Neurological manifestations can include [[tremor]]s, [[Chorea (disease)|chorea]], [[myopathy]], and in some susceptible individuals (in particular of Asian descent) [[Thyrotoxic periodic paralysis|periodic paralysis]]. An association between thyroid disease and [[myasthenia gravis]] has been recognized. Thyroid disease, in this condition, is [[autoimmune]] in nature and approximately 5% of people with myasthenia gravis also have hyperthyroidism. Myasthenia gravis rarely improves after thyroid treatment and the relationship between the two entities is notbecoming wellbetter understood.{{Citation needed|date=Aprilover 2010}}the past 15 years.<ref name="pmid16840920">{{cite journal | vauthors = Trabelsi L, Charfi N, Triki C, Mnif M, Rekik N, Mhiri C, Abid M | title = [Myasthenia gravis and hyperthyroidism: two cases] | language = French | journal = Annales d'Endocrinologie | volume = 67 | issue = 3 | pages = 265–9 | date = June 2006 | pmid = 16840920 | doi = 10.1016/s0003-4266(06)72597-5 }}</ref><ref>{{cite journal |first1=Rong-hua |last1=Song |first2=Qiu-ming |last2=Yao |first3=Bin |last3=Wang |first4=Qian |last4=Li |first5=Xi |last5=Jia |first6=Jin-an |last6=Zhang |title=Thyroid disorders in patients with myasthenia gravis: A systematic review and meta-analysis |journal=Autoimmunity Reviews |issue=10 |date=October 2019 |volume=18 |doi=10.1016/j.autrev.2019.102368 |pmid=31404702 |s2cid=199549144 |url=https://doi.org/10.1016/j.autrev.2019.102368 |access-date=2024-01-22}}</ref><ref>{{cite journal |vauthors=Zhu Y, Wang B, Hao Y, Zhu R |title=Clinical features of myasthenia gravis with neurological and systemic autoimmune diseases |journal=Front Immunol |date=September 2023 |volume=14 |issue=14:1223322 |doi=10.3389/fimmu.2023.1223322 |doi-access=free |pmid=37781409 |pmc= 10538566}} </ref>

[[File:Causes of hyperthyroidism.png|thumb|Most common causes of hyperthyroidism by age.<ref>{{cite journal | vauthors = Carlé A, Pedersen IB, Knudsen N, Perrild H, Ovesen L, Rasmussen LB, Laurberg P | title = Epidemiology of subtypes of hyperthyroidism in Denmark: a population-based study | journal = European Journal of Endocrinology | volume = 164 | issue = 5 | pages = 801–809 | date = May 2011 | pmid = 21357288 | doi = 10.1530/EJE-10-1155 | s2cid = 25049060 | doi-access = free }}</ref>]]

In overt primary hyperthyroidism, TSH levels are low and T₄ and T₃ levels are high. Subclinical hyperthyroidism is a milder form of hyperthyroidism characterized by low or undetectable serum TSH level, but with a normal serum free thyroxine level.<ref>{{cite journal | vauthors = Biondi B, Cooper DS | title = The clinical significance of subclinical thyroid dysfunction | journal = Endocrine Reviews | volume = 29 | issue = 1 | pages = 76–131 | date = February 2008 | pmid = 17991805 | doi = 10.1210/er.2006-0043 | doi-access = free }}</ref> Although the evidence for doing so is not definitive, treatment of elderly persons having subclinical hyperthyroidism could reduce the number of cases of [[atrial fibrillation]].<ref>{{cite journal | vauthors = Surks MI, Ortiz E, Daniels GH, Sawin CT, Col NF, Cobin RH, Franklyn JA, Hershman JM, Burman KD, Denke MA, Gorman C, Cooper RS, Weissman NJ | display-authors = 6 | title = Subclinical thyroid disease: scientific review and guidelines for diagnosis and management | journal = JAMA | volume = 291 | issue = 2 | pages = 228–238 | date = January 2004 | pmid = 14722150 | doi = 10.1001/jama.291.2.228 }}</ref> There is also an increased risk of [[bone fracture]]s (by 42%) in people with subclinical hyperthyroidism; there is insufficient evidence to say whether treatment with antithyroid medications would reduce that risk.<ref>{{cite journal | vauthors = Blum MR, Bauer DC, Collet TH, Fink HA, Cappola AR, da Costa BR, Wirth CD, Peeters RP, Åsvold BO, den Elzen WP, Luben RN, Imaizumi M, Bremner AP, Gogakos A, Eastell R, Kearney PM, Strotmeyer ES, Wallace ER, Hoff M, Ceresini G, Rivadeneira F, Uitterlinden AG, Stott DJ, Westendorp RG, Khaw KT, Langhammer A, Ferrucci L, Gussekloo J, Williams GR, Walsh JP, Jüni P, Aujesky D, Rodondi N | display-authors = 6 | title = Subclinical thyroid dysfunction and fracture risk: a meta-analysis | journal = JAMA | volume = 313 | issue = 20 | pages = 2055–2065 | date = May 2015 | pmid = 26010634 | pmc = 4729304 | doi = 10.1001/jama.2015.5161 }}</ref>

Some minimal effect on thyroid hormone production however also comes with [[propranolol]]—which has two roles in the treatment of hyperthyroidism, determined by the different isomers of propranolol. L-propranolol causes beta-blockade, thus treating the symptoms associated with hyperthyroidism such as tremor, palpitations, anxiety, and [[heat intolerance]]. D-propranolol inhibits thyroxine deiodinase, thereby blocking the conversion of T₄ to T₃, providing some though minimal therapeutic effect. Other beta-blockers are used to treat only the symptoms associated with hyperthyroidism.<ref>{{cite journal | vauthors = Eber O, Buchinger W, Lindner W, Lind P, Rath M, Klima G, Langsteger W, Költringer P | display-authors = 6 | title = The effect of D- versus L-propranolol in the treatment of hyperthyroidism | journal = Clinical Endocrinology | volume = 32 | issue = 3 | pages = 363–372 | date = March 1990 | pmid = 2344697 | doi = 10.1111/j.1365-2265.1990.tb00877.x | s2cid = 37948268 }}</ref> [[Propranolol]] in the UK, and [[metoprolol]] in the US, are most frequently used to augment treatment for people with hyperthyroid .<ref name=pmid1352658>{{cite journal | vauthors = Geffner DL, Hershman JM | title = Beta-adrenergic blockade for the treatment of hyperthyroidism | journal = The American Journal of Medicine | volume = 93 | issue = 1 | pages = 61–68 | date = July 1992 | pmid = 1352658 | doi = 10.1016/0002-9343(92)90681-Z }}</ref>

[[Surgery]] ([[thyroidectomy]] to remove the whole thyroid or a part of it) is not extensively used because most common forms of hyperthyroidism are quite effectively treated by the radioactive iodine method, and because there is a risk of also removing the [[parathyroid glands]], and of cutting the [[recurrent laryngeal nerve]], making swallowing difficult, and even simply generalized [[staphylococcus|staphylococcal]] infection as with any major surgery. Some people with Graves' may opt for surgical intervention. This includes those that cannot tolerate medicines for one reason or another, people that are allergic to iodine, or people that refuse radioiodine.<ref>{{cite journal | vauthors = Catania A, Guaitoli E, Carbotta G, Bianchini M, Di Matteo FM, Carbotta S, Nardi M, Fabiani E, Grani G, D'Andrea V, Fumarola A | display-authors = 6 | title = Total thyroidectomy for Graves' disease treatment | journal = La Clinica Terapeutica | volume = 164 | issue = 3 | pages = 193–196 | date = 2012 | pmid = 23868618 | doi = 10.7417/CT.2013.1548 }}</ref>

If people have toxic nodules treatments typically include either removal or injection of the nodule with alcohol.<ref>{{cite book |title=Endocrinology : adult and pediatric|date=2010|publisher=Saunders/Elsevier|location=Philadelphia|isbn=9781416055839978-1-4160-5583-9|page=Chapter 82|edition=6th|url=https://www.inkling.com/read/endocrinology-jameson-de-groot-6th/chapter-82/chapter082-reader-1 |url-access=subscription}}</ref>

| lastwork = AHFS Patient Medication Information [Internet]

| firstpublisher = American Society of Health-System Pharmacists, Inc

[[Signs and symptoms of Graves' disease#Sub-clinical hyperthyroidism|Subclinical hyperthyroidism]] modestly increases the risk of cognitive impairment and dementia.<ref>{{cite journal | vauthors = Rieben C, Segna D, da Costa BR, Collet TH, Chaker L, Aubert CE, Baumgartner C, Almeida OP, Hogervorst E, Trompet S, Masaki K, Mooijaart SP, Gussekloo J, Peeters RP, Bauer DC, Aujesky D, Rodondi N | display-authors = 6 | title = Subclinical Thyroid Dysfunction and the Risk of Cognitive Decline: a Meta-Analysis of Prospective Cohort Studies | journal = The Journal of Clinical Endocrinology and Metabolism | volume = 101 | issue = 12 | pages = 4945–4954 | date = December 2016 | pmid = 27689250 | pmc = 6287525 | doi = 10.1210/jc.2016-2129 }}</ref>

Recognizing and evaluating hyperthyroidism in pregnancy is a diagnostic challenge.<ref>{{cite journal | vauthors = Fumarola A, Di Fiore A, Dainelli M, Grani G, Carbotta G, Calvanese A | title = Therapy of hyperthyroidism in pregnancy and breastfeeding | journal = Obstetrical & Gynecological Survey | volume = 66 | issue = 6 | pages = 378–385 | date = June 2011 | pmid = 21851752 | doi = 10.1097/ogx.0b013e31822c6388 | s2cid = 28728514 }}</ref> Thyroid hormones are commonly elevated during the first trimester of pregnancy as the pregnancy hormone [[human chorionic gonadotropin]] (hCG) stimulates thyroid hormone production, in a condition known as gestational transient thyrotoxicosis.<ref name="Lee 2023" /> Gestational transient thyrotoxicosis generally abates in the second trimester as hCG levels decline and thyroid function normalizes.<ref name="Lee 2023" /> Hyperthyroidism can increase the risk of complications for mother and child.<ref name = "Moleti_2019">{{cite journal | vauthors = Moleti M, Di Mauro M, Sturniolo G, Russo M, Vermiglio F | title = Hyperthyroidism in the pregnant woman: Maternal and fetal aspects | journal = Journal of Clinical & Translational Endocrinology | volume = 16 | pages = 100190 | date = June 2019 | pmid = 31049292 | pmc = 6484219 | doi = 10.1016/j.jcte.2019.100190 }}</ref> Such risks include pregnancy-related hypertension, pregnancy loss, low-birth weight, [[pre-eclampsia]], [[preterm]] delivery, still birth and behavioral disorders later in the child's life.<ref name="Lee 2023" /><ref>{{Cite journal | vauthors = Krassas GE |date=2010-10-01 |title=Thyroid Function and Human Reproductive Health |url=https://academic.oup.com/edrv/article/31/5/702/2354820 |access-date=2022-05-31 |journal=Endocrine Reviews |series=Volume 31, Issue 5 |volume=31 |issue=5 |pages=702–755 |doi=10.1210/er.2009-0041|pmid=20573783 |doi-access=free }}</ref><ref name = "Moleti_2019" /><ref>{{cite journal | vauthors = Andersen SL, Andersen S, Vestergaard P, Olsen J | title = Maternal Thyroid Function in Early Pregnancy and Child Neurodevelopmental Disorders: A Danish Nationwide Case-Cohort Study | journal = Thyroid | volume = 28 | issue = 4 | pages = 537–546 | date = April 2018 | pmid = 29584590 | doi = 10.1089/thy.2017.0425 }}</ref> Nonetheless, high maternal FT4 levels during pregnancy have been associated with impaired brain developmental outcomes of the offspring and this was independent of hCG levels.<ref>{{cite journal | vauthors = Korevaar TI, Muetzel R, Medici M, Chaker L, Jaddoe VW, de Rijke YB, Steegers EA, Visser TJ, White T, Tiemeier H, Peeters RP | display-authors = 6 | title = Association of maternal thyroid function during early pregnancy with offspring IQ and brain morphology in childhood: a population-based prospective cohort study | journal = The Lancet. Diabetes & Endocrinology | volume = 4 | issue = 1 | pages = 35–43 | date = January 2016 | pmid = 26497402 | doi = 10.1016/S2213-8587(15)00327-7 | hdl = 1765/79096 }}</ref>

Hyperthyroidism is one of the most common endocrine conditions affecting older domesticated [[cat|housecats]]. In the United States, up to 10% of cats over ten years old have hyperthyroidism.<ref name="AAFP 2016">{{cite journal | vauthors = Carney HC, Ward CR, Bailey SJ, Bruyette D, Dennis S, Ferguson D, Hinc A, Rucinsky AR | display-authors = 6 | title = 2016 AAFP Guidelines for the Management of Feline Hyperthyroidism | journal = Journal of Feline Medicine and Surgery | volume = 18 | issue = 5 | pages = 400–416 | date = May 2016 | pmid = 27143042 | doi = 10.1177/1098612X16643252 | doi-access = free }}</ref> The disease has become significantly more common since the first reports of feline hyperthyroidism in the 1970s. The most common cause of hyperthyroidism in cats is the presence of [[benign tumors]] called adenomas. 98% of cases are caused by the presence of an adenoma,<ref>Johnson, A. (2014). &nbsp;Small Animal Pathology for Veterinarian Technicians. Hoboken: Wiley Blackwell.</ref> but the reason these cats develop such tumors continues to be studied.

Hyperthyroidism is much less common in [[dog]]s compared to cats.<ref>{{cite book| vauthors = Ford RB, Mazzaferro E |title=Kirk & Bistner's Handbook of Veterinary Procedures and Emergency Treatment|date=2011|publisher=Elsevier Health Sciences|location=London|isbn=9781437707991978-1-4377-0799-1|page=346|edition=9th}}</ref> Hyperthyroidism may be caused by a thyroid tumor. This may be a thyroid [[carcinoma]]. About 90% of carcinomas are very aggressive; they invade the surrounding tissues and [[Metastasis|metastasize]] (spread) to other tissues, particularly the lungs. This has a poor [[prognosis]]. Surgery to remove the tumor is often very difficult due to [[metastasis]] into [[arteries]], the [[esophagus]], or the [[windpipe]]. It may be possible to reduce the size of the tumor, thus relieving symptoms and allowing time for other treatments to work.{{Citation needed|date=April 2010}} About 10% of thyroid tumors are benign; these often cause few symptoms.{{Citation needed|date=April 2010}}

Hyperthyroidism may occur if a dog eats an excessive amount of thyroid gland tissue. This has occurred in dogs fed commercial dog food.<ref name="Broome 2015">{{cite journal | vauthors = Broome MR, Peterson ME, Kemppainen RJ, Parker VJ, Richter KP | title = Exogenous thyrotoxicosis in dogs attributable to consumption of all-meat commercial dog food or treats containing excessive thyroid hormone: 14 cases (2008-2013) | journal = Journal of the American Veterinary Medical Association | volume = 246 | issue = 1 | pages = 105–111 | date = January 2015 | pmid = 25517332 | doi = 10.2460/javma.246.1.105 | doi-access = free }}</ref>

== Further reading & Citations (MLA and APA) ==

* {{Cite journal |vauthors=Ross DS, etal |title=2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis |url=https://www.liebertpub.com/doi/full/10.1089/thy.2016.0229 |doi=10.1089/thy.2016.0229 |journal=Thyroid |volume=26 |issue=10 |date=Oct 2016 |pages=1343–1421|pmid=27521067 |doi-access=free }}

{{Medical condition classification and resources

| ICD10ICD11 = {{ICD10ICD11|E|05||e|005A02}}