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Diagnosis and Treatment of Subclinical Hyperthyroidism
J Korean Thyroid Assoc 2009;2(2):87-92
Published online November 30, 2009
© 2009 Korean Thyroid Association.

Young Suk Jo, MD, PhD

Division of Endocrinology, Department of Internal Medicine, Chungnam National University Hospital, Deajeon, Korea
This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Subclinical hyperthyroidism is relatively common clinical problem and is diagnosed by laboratory test with few clinical signs or symptoms. In definition, subclinical hyperthyroidism is designated to decrease in serum TSH below the reference range (0.45∼4.5 mIU/L) with normal serum thyroid hormone concentrations. Recently, improved sensitivity of assays and frequent assessment of serum thyroid stimulating hormone (TSH) have made clinicians require proper interpretation and management of subclinical hyperthyroidism. The causes of subclinical hyperthyroidism are similar to those of overt hyperthyroidism. However, in the view of evidence-based medicine, there are a lot of uncertainty about the definition, clinical importance, and necessity for prompt diagnosis and treatment of subclinical thyroid disease. This article reviewed thyroid hormone actions on heart, bone and metabolism with summary about recent guidelines for subclinical hyperthyroidism.
Keywords : Subclinical hyperthyroidism, Diagnosis, Treatment

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