Gary Brecka explains why hypothyroidism diagnoses often miss the real problem. Only 20% of circulating T3 comes from the thyroid itself; the other 80% is made elsewhere in the body from T4. Most low T3 cases get blamed on thyroid failure when the issue is actually in conversion or the pituitary's signaling.
If we look at the thyroid, let me just draw a beautiful picture here. You've been diagnosed with hypothyroid, likely because of this. So you have a thyroid gland right here in your neck, and usually what happens, you have a signal that leaves the pituitary called thyroid stimulating hormone. This is the volume knob, these are the speakers, and this is the tuner. As the pituitary increases thyroid stimulating hormone production of hormones rise. Vast majority of hypothyroid is diagnosed because you have low T3. Only 20% of the T3 is produced by the thyroid. 100% of the cases when your T3 is low, we hold the thyroid responsible for a crime it's not committing.
