Reverse T3, Serum

Metabolic Health

A healthy result should fall into the range 9.2 - 24.1 ng/dL.

Reverse T3 is a biologically inactive thyroid hormone; however, it does block the conversion of thyroxine (T4) to triiodothyronine (T3). Higher levels of reverse T3 can decrease the effect of thyroid hormone. While reverse T3 does not act like other thyroid hormones T3 and T4, it may play a role in brain development. Serum reverse T3 levels are helpful in distinguishing between thyroid disease and disease not related to the thyroid gland. Serum reverse T3 is often helpful when total T3, total T4, free T4, and TSH levels provide expected results or further investigation is needed. Because reverse T3 can be altered by illness, it is not useful in hospitalized patients.

Normal Ranges for serum reverse T3:

10-24 ng/dL

Reverse T3, Serum result calculator

insert the value from you Reverse T3, Serum test result.

What does it mean if your Reverse T3, Serum result is too low?

Decreased rT3 levels in the serum are uncommon. When it occurs, it usually happens in people with hypothyroidism or those being treated with growth hormones or steroids. Elevated rT3 does not specifically cause symptoms, but the thing that caused the increased rT3 level may cause its own symptoms.

Some specific causes of low reverse T3 are:

  • Central hypothyroidism
  • Growth hormone
  • Glucocorticoids
  • X-linked monocarboxylate transporter 8 deficiency

What does it mean if your Reverse T3, Serum result is too high?

Elevated reverse T3 (rT3) levels can be caused by almost any serious or prolonged illness. Low blood oxygen levels strongly increase reverse T3 levels in the serum. People with severe malnutrition (especially a lack of carbohydrates), severe diabetes, kidney, or liver disease have increased levels of rT3. Elevated rT3 does not specifically cause symptoms, but the disease that caused the increased rT3 level causes its own symptoms.

Some specific causes of high reverse T3 are:

  • Hyperthyroidism
  • Non-thyroidal illness syndrome/Euthyroid sick syndrome
  • Cirrhosis
  • Chronic renal failure
  • Protein-calorie malnutrition
  • Acute febrile illness
  • Carbohydrate deprivation
  • Uncontrolled diabetes mellitus
  • Amiodarone


Upload Full Test and Learn More

To learn more, visualize and track your test results, create a personal account.

Sign Up, Upload Tests, Get Insights and Improve with HealthMatters.io.

Sign up now.

Are you concerned about your blood test results?
Then get your personal health dashboard.

$5,99/month

Personal Plan +

Unlimited Tests Upload Subscription
Cancel anytime

Sign Up

$10/test

Personal Plan Basic

Single test upload.
Pay for each test result upload.

Upload Now

Your Privacy And Security

At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put security measures in place to help protect against the loss, misuse or alteration of information under our control. We use procedural, physical and electronic security methods designed to prevent people who aren't authorized from getting access to this information. Our internal code of conduct adds additional privacy protection. See our Privacy Policy for more information.