Subclinical hyperthyroidism

Am Fam Physician. 2011;83(8):933-938 Patient information: See related handout on Author disclosure: Dr. Braunstein is a consultant in reproductive endocrinology for Abbott Diagnostics. This affiliation is not related to the topic of this article. Dr. Donangelo has nothing to disclose. Article Sections Subclinical hyperthyroidism is defined by low or undetectable serum thyroid-stimulating hormone levels, with normal free thyroxine and total or free triiodothyronine levels. It can be caused by increased endogenous production of thyroid hormone (as in Graves disease or toxic nodular goiter), administration of thyroid hormone for treatment of malignant thyroid disease, or unintentional excessive thyroid hormone therapy. The rate of progression to overt hyperthyroidism is higher in persons who have suppressed thyroid-stimulating hormone levels compared with those who have low but detectable levels. Subclinical hyperthyroidism is associated with an increased risk of atrial fibrillation in older adults, and with decreased bone mineral density in postmenopausal women; however, the effectiveness of treatment in preventing these conditions is unknown. There is lesser-quality evidence suggesting an association between subclinical hyperthyroidism and other cardiovascular effects, including increased heart rate and left ventricular mass, and increased bone turnover markers. Possible associations between subclinical hyperthyroidism and quality of life parameters, cognition, and increase...

Subclinical Hyperthyroidism Subclinical hyperthyroidism is defined as a serum TSH that is lower than the reference range, with free thyroxine and T3 concentrations that are within the reference range. From: Encyclopedia of Endocrine Diseases (Second Edition), 2017 Related terms: • Thyroid Gland • Hypothyroidism • Thyroid Disease • Therapeutic Procedure • Patient • Inpatient • Thyroid Hormone • Hormone Determination • Hyperthyroidism • Thyrotropin SHyper can be associated with signs and symptoms of mild thyroid hormone excess resembling adrenergic over activity ( Biondi et al., 1993, 1994). In general, SHyper negatively affects the quality of life of adult patients and induces supraventricular arrhythmias (atrial premature beats in middle-aged people and atrial fibrillation in the elderly) ( Biondi et al., 1993, 1994, 1996, 2000; Sawin et al., 1994). Various authors have reported SHyper patients scoring higher on a symptom rating scale (specifically designed for clinically overt hyperthyroid patients) than euthyroid controls ( Biondi et al., 1993, 1994; Mercuro et al., 2000 ). These findings clearly indicate that the term “ subclinical hyperthyroidism” is a misnomer. Patients with persistent SHyper can have important alterations involving the morphology and function of the cardiovascular system and/or bone and mineral metabolism ( Table 1) ( Biondi et al., 1993, 1994, 1996, 2000; Mercuro et al., 2000; Fazio et al., 1995). Therefore, SHyper is not merely a laboratory conditi...

Our first area of inquiry involved the diagnostic evaluation that would be recommended after the diagnosis of subclinical hyperthyroidism was made and confirmed in the four cases. Approximately 50%–70% of respondents recommended further evaluation in all four cases. The most commonly ordered tests were the RAIU, thyroid scan and antithyroid antibody (TPO and Tg) testing while TRAb and TSI measurements and thyroid ultrasounds were ordered less frequently. Severity of disease appeared to effect the frequency of testing as respondents were significantly more likely to order further testing in the patients with undetectable serum TSH levels than they were in the patients with low but detectable serum TSH levels. Our results verify that most practitioners consider subclinical hyperthyroidism to be a condition that warrants further evaluation. Endogenous subclinical hyperthyroidism is generally caused by milder or early forms of the same conditions that cause overt hyperthyroidism. [ We next sought opinions regarding whether or not these patients should be offered active treatment. A large majority (84%) of the respondents recommended observation rather than active treatment in the young woman with a low but detectable serum TSH level, regardless of whether the underlying etiology was probable Graves' disease or a toxic MNG. A smaller majority recommended observation alone in the younger woman with an undetectable serum TSH (58%) and in the older woman with a low but detectable ...

Continuing Education Activity Hyperthyroidism is a common thyroid disorder with multiple underlying etiologies. This disease is characterized by excess thyroid hormone production. Hyperthyroidism can be overt or subclinical. Overt hyperthyroidism is defined as low or suppressed thyroid stimulating hormone (TSH) levels with elevated triiodothyronine (T3) levels and/or elevated thyroxine (T4) levels. Hyperthyroidism is associated with significant short-term and long-term morbidity. Therefore, early recognition of this condition and timely instruction of appropriate therapy is critical. This activity reviews the etiology, presentation, evaluation, and management of hyperthyroidism and reviews the role of the interprofessional team in evaluating, diagnosing, and managing the condition. Objectives: • Review the various etiologies that lead to a presentation of hyperthyroidism. • Describe the presentation and expected examination findings when evaluating a patient with hyperthyroidism. • Summarize the various treatment options available for hyperthyroidism, depending on specific etiology. • Explain the importance of interprofessional team strategies for improving care coordination and communication to aid in prompt diagnosis of hyperthyroidism and improving outcomes in patients diagnosed with the condition. Introduction Hyperthyroidism is a common thyroid disorder. "Hyperthyroidism" defines a syndrome associated with excess thyroid hormone production. Hyperthyroidism can be over...