Hyperthyroidism resident survival guide
Hyperthyroidism is a disease that results from thyroid hormone-induced hypermetabolism. The excess thyroid hormone is released from the thyroid gland as a result of excess thyroid hormone production, or by processes that disrupt the follicular structure of the gland with subsequent release of stored hormone. Most patients with severe hyperthyroidism present with a dramatic symptom constellation. Hyperthyroidism's typical symptoms include palpitations, heat intolerance, increased bowel movement, frequent tremors, anxiety, weight loss despite normal or increased appetite and shortness of breath. Goiter is commonly found on physical examination. As a physician, it is important to identify the severity of clinical signs, thyroid storm and treat them promptly. This section provides a short and straight-to-the-point overview of hyperthyroidism.
- Graves disease
- Painless or transient (silent) thyroiditis
- Toxic adenoma (Plummer disease)
- Toxic multinodular goiter
- Postpartum thyroiditis
- Hyeremesis gravidarum
- Subacute granulomatous (de Quervain) thyroiditis
- Drug-induced thyroiditis
Clinical assessment of signs & symptoms for hyperthyroidism:
|Measure serum Thyroid-stimulating hormone levels|
|Low TSH (usually <0.01mU/L)||High TSH|
|Mild hyperthyroidism: Serum T4 and T3 values in normal range or only T3 levels are elevated.||Overt hyperthyroidism: Both serum T3 and T4 levels elevated||Elevated serum T4 and T3 levels|
|Perform thorough physical examination of thyroid gland and look for signs for thyroid eye disease. Thyroid gland diffusely enlarged with symmetrical hypertrophy and new onset of ocular symptoms||Repeat TSH levels in serial dilution|
|Yes. Graves' disease||No||Positive||Negative|
|Measure serum assays of TRAb and radioactive iodine uptake thyroid scan||High TSH levels due to hetrophilic antibodies||Look out for pituitary lesion|
|Measurement of serum levels of human anti-mouse antibodies|
|Diffuse increase in iodine uptake||Localized increase in iodine uptake||Subnormal or absent uptake of iodine|
|Graves' disease||Toxic nodular goiter||Subacute thyroiditis/ Postpartum thyroiditis||Factitious ingestion of thyroid hormones||Excess intake of iodine recently|
|High levels of thyroglobulin in serum||Low thyroglobulin levels||Measure spot urine iodine or 24 hour urine iodine level|
|Overt Graves' disease|
|Antithyroid medications||Radioactive iodine ablation||Surgery|
- Beta-blockers are recommended for symptomatic relief of systemic symptoms like tachycardia, anxiety, and tremors. It is strongly recommended for elderly patients with a resting heart rate greater than 90 beats per minute and coexisting cardiovascular diseases.
- The total T3 to T4 plasma levels ratio can assess the etiology of thyrotoxicosis in patients in whom the radioactive iodine uptake scan is contraindicated. An overactive thyroid gland will release more T3 compared to T4. Hence in Graves’ disease and toxic nodular goiter total T3 to T4 ratio will be high (i.e. >20), while in sub-acute or post-partum thyroiditis, the ratio of T3 to T4 will be low (i.e. <20). 
- TRAb is faster and more cost-effective compared to radioactive iodine thyroid uptake scan to diagnose Graves’ disease. It should be preferred for the diagnosis of Graves’ disease.
- Near-total or total thyroidectomy is the treatment of choice for toxic multinodular goiter. Isolated lobectomy or isthmusectomy is carried out for toxic adenoma. Radioactive iodine ablation therapy have resulted in severe thyrotoxicosis with worsening of cardiac rhythms including supraventricular tachycardia, atrial flutter or atrial fibrillations in patients with non-toxic and toxic multi-nodular goiter.
- Pregnant, lactating females, patients with co-existing thyroid malignancy or those with high clinical suspicion of thyroid cancer should avoid radioactive iodine ablation therapy. Non-pregnant females should plan a pregnancy at least six months after RIA.
- Anti-thyroid medications are contraindicated in patients who experience anaphylaxis or serious adverse reactions from the medications.
- Elderly patients with co-existing severe cardiac, pulmonary diseases, or decreased surgical access should avoid thyroid surgery. Thyroidectomy is also contraindicated in pregnant females during the first and third trimester of pregnancy as anesthetic drugs have teratogenic effects on a developed fetus. There in an increased risk of abortion in the first trimester and preterm delivery in the third trimester. The ideal time for thyroidectomy in pregnant females is during the second trimester. There is also an increased incidence of intraoperative adverse reactions like hypocalcemia and recurrent laryngeal nerve injury in pregnant patients.
- Kravets I (2016). "Hyperthyroidism: Diagnosis and Treatment". Am Fam Physician. 93 (5): 363–70. PMID 26926973.
- Vanderpump MP (2011). "The epidemiology of thyroid disease". Br Med Bull. 99: 39–51. doi:10.1093/bmb/ldr030. PMID 21893493.
- Pearce EN, Farwell AP, Braverman LE (2003). "Thyroiditis". N Engl J Med. 348 (26): 2646–55. doi:10.1056/NEJMra021194. PMID 12826640.
- "Correction to: Thyroid 2016;26:1343-1421. DOI: 10.1089/thy.2016.0229". Thyroid. 27 (11): 1462. 2017. doi:10.1089/thy.2016.0229.correx. PMC 5672663. PMID 29035639.
- Ross, Douglas S.; Burch, Henry B.; Cooper, David S.; Greenlee, M. Carol; Laurberg, Peter; Maia, Ana Luiza; Rivkees, Scott A.; Samuels, Mary; Sosa, Julie Ann; Stan, Marius N.; Walter, Martin A. (2016). "2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis". Thyroid. 26 (10): 1343–1421. doi:10.1089/thy.2016.0229. ISSN 1050-7256.
- Nwatsock, JF; Taieb, D; Tessonnier, L; Mancini, J; Dong-A-Zok, F; Mundler, O (2012). "Radioiodine Thyroid Ablation in Graves′ Hyperthyroidism: Merits and Pitfalls". World Journal of Nuclear Medicine. 11 (1): 7. doi:10.4103/1450-1147.98731. ISSN 1450-1147.
- Carlé A, Knudsen N, Pedersen IB, Perrild H, Ovesen L, Rasmussen LB; et al. (2013). "Determinants of serum T4 and T3 at the time of diagnosis in nosological types of thyrotoxicosis: a population-based study". Eur J Endocrinol. 169 (5): 537–45. doi:10.1530/EJE-13-0533. PMID 23935127.
- Shigemasa C, Abe K, Taniguchi S, Mitani Y, Ueda Y, Adachi T; et al. (1987). "Lower serum free thyroxine (T4) levels in painless thyroiditis compared with Graves' disease despite similar serum total T4 levels". J Clin Endocrinol Metab. 65 (2): 359–63. doi:10.1210/jcem-65-2-359. PMID 3110204.
- McKee A, Peyerl F (2012). "TSI assay utilization: impact on costs of Graves' hyperthyroidism diagnosis". Am J Manag Care. 18 (1): e1–14. PMID 22435785.
- Koornstra JJ, Kerstens MN, Hoving J, Visscher KJ, Schade JH, Gort HB; et al. (1999). "Clinical and biochemical changes following 131I therapy for hyperthyroidism in patients not pretreated with antithyroid drugs". Neth J Med. 55 (5): 215–21. doi:10.1016/s0300-2977(99)00066-2. PMID 10593131.
- Kuy S, Roman SA, Desai R, Sosa JA (2009). "Outcomes following thyroid and parathyroid surgery in pregnant women". Arch Surg. 144 (5): 399–406, discussion 406. doi:10.1001/archsurg.2009.48. PMID 19451480.
- Weingold AB (1983). "Appendicitis in pregnancy". Clin Obstet Gynecol. 26 (4): 801–9. doi:10.1097/00003081-198312000-00005. PMID 6661836.