T3 Reverse


For: ,

Quest Diagnostics Test Code: 90963

rT3, also known as reverse triiodothyronine, is a hormone that is released from the thyroid gland. It is not the same as T3. This hormone is not a very large proportion of thyroid hormones. The reverse T3 test is to diagnose euthyroid sick syndrome, when there is a derangement in the T3, T4 and TSH values, but not enough clinical evidence of specifically thyroid signs and symptoms. This condition can occur with a host of medical issues, including, but not limited to renal, respiratory and gastrointestinal disorders. The diagnosis of this disorder will see a high rT3 value, with the other thyroid function tests being either normal or minimally deranged.

This test is performed in following conditions such as:

• Gastrointestinal diseases
• Pulmonary diseases
• Cardiovascular diseases
• Renal diseases
• Infiltrative and metabolic disorders
• Inflammatory conditions

Also Known As: Triiodothyronine (T3) Reverse


This Reverse T3 test has no fasting requirements.


Specimen Collected
  • Blood
Estimated Time Taken

Turnaround time for the Reverse T3 test is typically 3-5 business days.