Value of the high or low T3 exam: what can it be?

Expert answer:

The reference values of the T3 examination may vary depending on the method and reagent used, therefore, these values ​​should be clearly stated in the results reports of laboratory tests.

  • Up to 3 days of age: 100 to 740 ng / dL
  • 1 to 11 months of age: 105 to 245 ng / dL
  • 1 to 5 years: 105 to 269 ng / dL
  • 6 to 10 years: 94 to 241 ng / dL
  • 11 to 15 years: 82 to 213 ng / dL
  • 16 to 20 years: 80 to 210 ng / dL
  • 20 to 50 years: 70 to 204 ng / dL
  • 50 to 90 years: 40 to 181 ng / dL

The T3 test is the dosage of a hormone produced by the thyroid gland, known as triiodothyronine. The evaluation of serum levels of T3 is recommended for people with TSH
decreased and total or free T4 within the reference values. Thus, this test is important in the evaluation of hyperthyroidism, more specifically thyrotoxicosis.

One more level high of T3 may indicate hyperthyroidism, Graves' disease or possibly thyroid cancer. T3 low may be a sign of chronic non-thyroid diseases and their serum levels are influenced by nutritional status. They may also occur in hypothyroidism or Hashimoto's disease.

In addition, pregnancy and some problems in the liver can make to raise T3 levels artificially. Variations in the concentration of thyroxine binding globulin (TBG) and other proteins may affect T3 levels.

The interpretation of the results of the examination should be performed by the doctor who requested it, together with the history and clinical examination. For more information, see a general practitioner or endocrinologist.