Have you long suspected you had thyroid problems but your test results come back “normal”? Maybe you’re not being testing thoroughly! Commonly a routine thyroid screening only involves testing the Thyroid Stimulating Hormone (TSH). TSH is produced by the pituitary gland in response to low circulating levels of thyroid hormone (T4). The TSH alone cannot be used to screen for secondary hypothyroidism and usually requires a measurement of thyroid hormone levels to be adequately interpreted. A screening of T4 (thyroxine) and T3 (triiodothyronine) in addition to TSH are helpful in determining thyroid function. T4 and some T3 are produced by the thyroid. T4 converts to T3 outside the thyroid in most all tissue with the liver and kidney doing the most conversion. Most of the T3 (80%) is produced outside the thyroid. T3 is most responsible for increasing metabolic rate.

When T4 becomes T3, this causes energy to be made in each living cell. T4 can also become Reverse T3 (RT3) which reduces the energy production in the cell. Just as a car needs an accelerator and brakes for proper function, the same is true for the body. The body needs T3 (the accelerator) and RT3 (the brake) to manage its energy needs.

If you have a low TSH, it could mean several things:

  • normal thyroid function with optimal T3 and T4
  • overactive thyroid gland with high T3 and T4
  • Secondary Hypothyroidism with low T3 and T4 indicates pituitary gland dysfunction

If you have a high TSH, it could mean:

  • Under-active thyroid gland with low or normal T3 and T4
  • Rare is pituitary gland tumor

Is It Really the Thyroid? Because 80% of T3 is produced outside the thyroid, what appears, clinically, to be low thyroid function could actually have nothing to do with the thyroid gland. Many environmental factors, illnesses and drugs affect conversion of T4 to T3.

Many environmental exposures can affect your thyroid function. See the side bar for environmental aspects you should be aware of. As mentioned previously, maintaining good iodine status is one way to support thyroid function and combat these environmental exposures but there are other minerals and amino acids necessary for adequate thyroid hormone production.

Would you like to be tested properly to determine how your thyroid is doing? Set up a nutritional consultation today. You can’t base your health on how you feel. Get tested today to get the facts on your health status.