Laboratory Studies

Typical NTI findings are T4 level within the reference range, low T3 level, slightly reduced or reference range level of TSH, elevated rT3 level, and a free T4 level that is within the reference range or is elevated.

In severe NTI, the findings are low T4, low T3, reduced TSH, elevated rT3, and free T4 that is within the reference range or is diminished.

Recommended tests include the following:

Total T4
Total T3
TSH
Free T4
rT3
Free T3

Refer to specific nonthyroidal diseases for particular alterations in thyroid function test results.

Imaging Studies

No specific imaging study can be used to diagnose an NTI.

Thyroid sonogram, thyroid uptake and scan, and other radiological studies have no role in the diagnosis of NTI.

Procedures

Thyroid biopsy has no role in the diagnosis of NTI.

Histologic Findings

No typical histological findings of thyroid biopsies in NTI exist.

Staging

No established clinical staging of NTI exists; abnormalities of thyroid function test findings are proportional to the severity and duration of NTI.

Treatment & Management

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Media Gallery

Euthyroid sick syndrome. Relationship between serum thyroid hormone concentrations and severity of nonthyroidal illness (NTI). Abbreviations: reverse triiodothyronine (rT3), thyroid-stimulating hormone (TSH), free thyroxine (FT4), thyroxine (T4), triiodothyronine (T3).
Euthyroid sick syndrome. Relationship between severity and duration of nonthyroidal illness (NTI) and thyroid hormone levels. Abbreviations: reverse triiodothyronine (rT3), free thyroxine (free T4), thyroxine (T4), triiodothyronine (T3).

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Author

Serhat Aytug, MD, FACE Endocrinologist, Division of Endocrinology, Diabetes and Metabolism, St Jude Heritage Medical Group; Associate Professor of Medicine – Endocrinology, Diabetes and Metabolism, Council of Higher Education of Turkey

Serhat Aytug, MD, FACE is a member of the following medical societies: American Association of Clinical Endocrinologists, Endocrine Society

Disclosure: Nothing to disclose.

Coauthor(s)

Lawrence E Shapiro, MD Chief, Division of Endocrinology and Metabolism, Professor of Medicine, Department of Medicine, Winthrop University Hospital

Lawrence E Shapiro, MD is a member of the following medical societies: American Diabetes Association, American Thyroid Association, Endocrine Society

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Don S Schalch, MD Professor Emeritus, Department of Internal Medicine, Division of Endocrinology, University of Wisconsin Hospitals and Clinics

Don S Schalch, MD is a member of the following medical societies: American Diabetes Association, American Federation for Medical Research, Central Society for Clinical and Translational Research, Endocrine Society

Disclosure: Nothing to disclose.

Chief Editor

Romesh Khardori, MD, PhD, FACP (Retired) Professor, Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, Eastern Virginia Medical School

Romesh Khardori, MD, PhD, FACP is a member of the following medical societies: American Association of Clinical Endocrinologists, American College of Physicians, American Diabetes Association, Endocrine Society

Disclosure: Nothing to disclose.

Additional Contributors

Steven R Gambert, MD Professor of Medicine, Johns Hopkins University School of Medicine; Director of Geriatric Medicine, University of Maryland Medical Center and R Adams Cowley Shock Trauma Center

Steven R Gambert, MD is a member of the following medical societies: Alpha Omega Alpha, American Association for Physician Leadership, American College of Physicians, American Geriatrics Society, Endocrine Society, Gerontological Society of America, Association of Professors of Medicine

Disclosure: Nothing to disclose.