INTRODUCTION

THESE UPDATED CLINICAL PRACTICE GUIDELINES (CPGs) (1–3) summarize the recommendations of the authors, acting as a joint American Association of Clinical Endocrinologists (AACE) and American Thyroid Association (ATA) task force for the diagnostic evaluation and treatment strategies for adults with hypothyroidism, as mandated by the Board of Directors of AACE and the ATA.

The ATA develops CPGs to provide guidance and recommendations for particular practice areas concerning thyroid disease, including thyroid cancer. The guidelines are not inclusive of all proper approaches or methods, or exclusive of others. the guidelines do not establish a standard of care, and specific outcomes are not guaranteed. Treatment decisions must be made based on the independent judgment of health care providers and each patient's individual circumstances. A guideline is not intended to take the place of physician judgment in diagnosing and treatment of particular patients (for detailed information regarding ATA guidelines, see the Supplementary Data, available online at www.liebertpub.com/thy).

The AACE Medical Guidelines for Clinical Practice are systematically developed statements to assist health care professionals in medical decision making for specific clinical conditions. Most of their content is based on literature reviews. In areas of uncertainty, professional judgment is applied (for detailed information regarding AACE guidelines, see the Supplementary Data).

These guidelines are a document that reflects the current state of the field and are intended to provide a working document for guideline updates since rapid changes in this field are expected in the future. We encourage medical professionals to use this information in conjunction with their best clinical judgment. The presented recommendations may not be appropriate in all situations. Any decision by practitioners to apply these guidelines must be made in light of local resources and individual patient circumstances.

The guidelines presented here principally address the management of ambulatory patients with biochemically confirmed primary hypothyroidism whose thyroid status has been stable for at least several weeks. They do not deal with myxedema coma. The interested reader is directed to the other sources for this information (4). The organization of the guidelines is presented in Table 1.

Serum thyrotropin (TSH) is the single best screening test for primary thyroid dysfunction for the vast majority of outpatient clinical situations, but it is not sufficient for assessing hospitalized patients or when central hypothyroidism is either present or suspected. The standard treatment is replacement with L-thyroxine which must be tailored to the individual patient. The therapy and diagnosis of subclinical hypothyroidism, which often remains undetected, is discussed. L-triiodothyronine in combination with L-thyroxine for treating hypothyroidism, thyroid hormone for conditions other than hypothyroidism, and nutraceuticals are considered.