Women are the most intuitive patients that I work with. When they tell me they just feel ‘off’ or that they are exhausted, anxious, constipated, and unable to lose weight no matter how well they stick to their clean diets—they’re usually onto something. After a few more questions from me to confirm or tie together symptoms, and we often run a full thyroid panel to make sure that everything is in working order. Many times, I’m told by my female patients, “My primary care doctor already checked my thyroid and said that I was fine—it must be something I’m eating.” And here’s where it begins. When a conventional medical professional “checks thyroid function,” they’re usually only running your TSH, or thyroid stimulating hormone. This is the brain hormone that is sent to your thyroid to tell it to get to work. If it’s within normal limits, your conventional doctor assumes your thyroid is working properly. From a functional medicine perspective, I’ve seen time and time again that this assumption doesn’t reveal the entire picture, and can leave patients suffering with low thyroid.
To get a deeper look into your thyroid function, there are are a few more tests that your doctor should run to get the full thyroid picture:
- Free T4: T4 is the inactive thyroid hormone that is output by your thyroid gland. Measuring this tells us if your thyroid gland is actually outputting enough hormone to be utilized. The free, and bioavailable, form of T4 is the best to measure.
- Free T3: The inactive T4 then gets converted (through enzymes called deiodinase enzymes) into active T3. T3 is what gives you the energy, metabolism, hair growth, and bowel regularity that many women are concerned about. This lab test tells us if your body is able to convert inactive thyroid hormone to active thyroid hormone in enough quantity to make you feel better and get your physiology up and running.
- Reverse T3 (RT3): If your T3 cannot be taken up into your cells for any reason, it gets flipped around (hence, reverse T3, or the reverse of T3) and stored as an inactive product. We are finding that your pituitary gland (the part of your brain that releases TSH) can’t distinguish between actual T3, and RT3, and that higher levels of RT3 can trick your pituitary gland into thinking your thyroid is functioning normally, causing your TSH to be normal.
- Thyroid Antibodies: Probably one of the most underdiagnosed thyroid dysfunctions is the autoimmune component, Hashimoto’s Thyroiditis. Without treatment of Hashimoto’s, the continual damage to the thyroid gland by these antibodies can create a non-functioning gland later in life. The antibodies to test for Hashimoto’s is anti-thyroglobulin and anti-thyroperoxidase.