Why Most Thyroid Tests are Incomplete
If you’ve ever suspected that you have a thyroid issue, you probably have experienced the frustration of being told that your labs are totally normal. What this usually means is that your TSH and maybe T4 are normal. The problem is, these are only two possible markers used to assess thyroid health- they definitely don’t tell the complete story!
One goal of integrative nutrition is to address subclinical issues before they progress to a point where it’s hard to correct these issues. In order to detect subclinical thyroid imbalances before they become full-blown issues, a FULL thyroid panel needs to be run as a screening tool. Unfortunately, usually only TSH and T4 are looked at, which causes a lot of thyroid issues to go undetected.
If you suspect you have a thyroid disorder, you want to ask your doctor to run a FULL thyroid panel, which includes all of the following:
TSH is the marker your doctor will run to check you thyroid function. The funny thing is, this marker doesn’t directly test your thyroid function. TSH, or thyroid stimulating hormone, is a hormone produced by your pituitary gland to tell the thyroid gland to make more thyroid hormone. Because the brain-thyroid connection uses a negative feedback loop, high TSH actually indicates an UNDERactive thyroid, and low TSH indicates and OVERactive thyroid.
T4 is the main thyroid hormone that your thyroid gland directly makes. After T4 is made by the thyroid gland, some of it must be converted to T3.
T3 is about 3-4 times more potent than T4. About 1/3 of the T4 in your body will be converted to T3. This conversion process largely takes place in the liver and the gut, so the health of these systems is integral to this conversion process.
Reverse T3 is a more complicated and advanced thyroid marker. It is similar in structure to T3, but it metabolically inactive. Under stress, the body will convert more T4 to reverse T3 to slow down the metabolism and conserve resources.
TPO and TBG antibodies are used to screen for Hashimoto’s Thyroiditis, an autoimmune condition that affect thyroid function. Some sources estimate that 90% of those with hypothyroidism in the US actually have Hashimoto’s, but many are unaware because this isn’t commonly screened for. Even when someone is found to have Hashimoto’s, conventional medicine treats this condition with thyroid medication instead of addressing the root of the autoimmune condition.
TSI antibodies are used to screen for Grave’s disease, another autoimmune condition affecting the thyroid.
References:
Cooper, D.S. & Biondi, B (2012). Subclinical thyroid disease. Lancet, 379(9821), 1142-1154. doi: 10.1016/S0140-6736(11)60276-6