Functional Hypothyroidism: When Normal Isn’t Normal

The thyroid is a butterfly-shaped gland in your neck that’s responsible for secreting a critical hormone called triiodothyronine or “T3”.

T3 is the active form of the thyroid hormone. It’s the body’s “accelerator,” regulating body temperature, heart rate, body weight, and glucose/cholesterol management. T3 is essentially responsible for controlling cell metabolism in every cell in your body, promoting optimal growth, function, and maintenance of all body tissues.

Needless to say, it’s a pretty important hormone.

Enter rT3, the Evil Twin

Your body also has reverse T3 (rT3), T3’s evil twin. This pesky hormone is a mirror image of T3. It can attach itself to T3 receptors, but because it’s shape is different, it doesn’t fit properly and fails to activate them. In doing so, it blocks T3 from plugging-in, thus inactivating the accelerator.

Under normal circumstances, your body produces about 60% T3 and 40% rT3. That means the rT3 is “outgunned” and things work as they’re supposed to.

Here’s the catch: Reverse T3 production increases in direct response to stress of any kind. Cortisol, the stress hormone, effectively inhibits our ability to produce T3 AND promotes the production of rT3– a double whammy. Under high, prolonged stress, so much rT3 is produced that it blocks almost all of the T3 receptors and normal T3 is completely, or almost completely, inactivated.

What happens now? You get all the symptoms of hypothyroidism (low thyroid function):

  • Fatigue
  • Increased sensitivity to cold
  • Constipation
  • Dry skin
  • Unexplained weight gain
  • Puffy face
  • Hoarseness
  • Muscle weakness
  • Elevated blood cholesterol level
  • Muscle aches and pain
  • Pain, stiffness or swelling in your joints
  • Heavier than normal or irregular menstrual periods
  • Thinning hair
  • Slower heart rate
  • Depressed mood
  • Impaired memory

Here’s the critical part. Conventional medical approaches typically don’t measure T3 and rT3 levels, so your lab tests for related hormones like TSH (thyroid stimulating hormone) and T4 (the “raw material” from which T3 and rT3 are made) can look normal.

The Solution

Most medical doctors do not recognize rT3 dominance theory or functional hypothyroidism, and will not prescribe T3. Conventional medicine only recognizes thyroid gland deficiency.

This isn’t a thyroid gland deficiency. It’s an imbalance of T3 to rT3, most often caused by prolonged stress. This is easily treated with stress management and a prescription for T3.

Questions about your thyroid or any of the symptoms above? You can have your rT3 and T3 levels measured by contacting the clinic.