Reverse Triiodothyronine
RT3
Description
"Reverse Triiodothyronine (rT3)" test measures levels of inactive rT3, which can interfere with thyroid hormone function. Doctors often recommend this test when symptoms like fatigue, weight gain, or cold sensitivity persist despite normal thyroid labs. Elevated rT3 may suggest stress-related hormone imbalances or poor T4-to-T3 conversion. This test provides a deeper look into thyroid activity and metabolic function. Results help tailor treatment strategies, such as medication adjustments or lifestyle changes, to support energy and hormonal balance.
Category
Hormones
Procedure
Invasive
Sample Type
Blood – Serum
Units
Nanograms Per Deciliter
Procedure Category
Blood Draw
Test Group
Complete Thyroid Group
Test Group Description
Complete Thyroid Group: A comprehensive array of tests for a thorough evaluation of thyroid function, providing detailed insights into thyroid health and associated conditions.
Optimal Range
For All Individuals:
Conventional Unit: <15.00 ng/dL
SI Unit: Not Frequently Used
Normal Range
For All Individuals:
Conventional Unit: 9.20–24.10 ng/dL
SI Unit: Not Frequently Used
Results That Differ From The Norm (Direct and Indirect Causes)
Increased levels may indicate:
Chronic kidney disease
Cardiovascular disease (Disorders affecting the heart and blood vessels)
Euthyroid sick syndrome (Abnormal thyroid function in non-thyroidal illness)
Hepatic failure (Liver dysfunction)
Low T3 syndrome (Reduced levels of triiodothyronine)
Medications (such as beta-bl...
Key Reasons For Testing
Thyroid Function Assessment: Provides insights into thyroid hormone metabolism and T4 to rT3 conversion.
Euthyroid Sick Syndrome Diagnosis: Helps diagnose ESS in critically ill patients with altered thyroid function.
Critical Illness Prognosis: Serves as a prognostic indicator, with elevated levels linked to illness severity and mortality risk.
Peripheral Thyroid Hormone Metabolism: Differentiates central and peripheral causes of thyroid dysfunction to guide treatment.
Health Status Conditions It May Be Used To Assess
Currently, this test is not directly associated with any conditions listed on the Health Status page. However, it may be included as part of a broader set of tests linked to specific health conditions.
Some Prominent Medical Labs That May Offer This Test
Please note that this particular test has not been associated with any of the listed prominent medical labs. We recommend enquiring with your private physician or nearest hospital to determine where this specific test can be performed.
References
Important Note
Any medical procedure yielding results outside the norm may be directly or indirectly linked to the conditions outlined on this page. Various factors, including genetics, medication and supplement usage, recent illnesses, pregnancy, pre-test eating, smoking, and stress, can impact the test's outcome. Additionally, factors like false positives, false negatives, inaccurate analyses, and others can influence results.
Reference ranges, which help healthcare professionals interpret medical tests, may vary depending on age, gender, and other factors. They may also differ between laboratories due to variations in instruments and methods used. Optimal ranges are designed for preventive purposes, aiming to identify trends and potential risks early, while normal ranges reflect conventional laboratory values indicating no current disease or pathology. Your healthcare practitioner may have specific reasons for testing that deviate from the usual or may interpret results differently based on individual circumstances. Proper interpretation typically involves considering clinical findings and other diagnostic tests. Hence, it is crucial to provide your healthcare professionals with a comprehensive medical history, consult with them for result interpretation, and follow their guidance for potential re-testing or additional diagnostics.
Disclaimer
This content is provided solely for informative and educational purposes. It is not intended as a substitute for medical advice or treatment from a personal physician. Regarding the interpretation of their medical test results and/or specific health questions, it is recommended that all readers and viewers consult their physicians or other qualified health professionals. The publisher is not responsible for any adverse health effects that may result from reading or following the information in this educational content. Before beginning any nutrition, supplement, or lifestyle program, all viewers, especially those taking prescription or over-the-counter medications, should consult their physician or health care practitioner.
Please note that while prominent lab names are included in this content, we cannot guarantee that these labs offer all the tests mentioned. For confirmation, individuals should contact the labs directly or consult their medical practitioners. The information provided reflects general knowledge at the time of publication and may not include recent updates or emerging research. Readers should verify details with qualified professionals to ensure the most up-to-date and accurate guidance.
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