Many people struggling with fatigue, weight gain, brain fog, and mood swings are told their thyroid is “normal” because their TSH (thyroid-stimulating hormone) falls within the standard range. However, TSH alone does not provide the full picture of thyroid health. When symptoms persist despite a normal TSH, there may be deeper imbalances that require further testing.
Thyroid Hormones: More Than Just TSH
TSH is a signal from the brain that tells the thyroid how much hormone to produce, but it does not measure how well the body is using those hormones. The thyroid produces T4, which must be converted into the active form, T3, for the body to use. If this conversion is not happening properly, symptoms like fatigue, brain fog, and weight gain can continue, even with a normal TSH. Measuring Free T3 and Free T4 levels is crucial to understanding true thyroid function.
Reverse T3: The Thyroid Brake Pedal
When the body is under stress, dealing with inflammation, or lacking key nutrients, it may produce too much Reverse T3 (RT3). Reverse T3 blocks the action of active T3, slowing down metabolism and causing low-energy symptoms. High RT3 levels can create a condition where the body technically has enough thyroid hormone but cannot use it effectively. Checking Reverse T3 levels can uncover this hidden imbalance.
Thyroid Antibodies and Autoimmune Conditions
Some thyroid conditions, like Hashimoto’s thyroiditis, are autoimmune disorders where the immune system attacks the thyroid. This can cause fluctuating symptoms long before TSH becomes abnormal. Testing for thyroid antibodies (TPO and TG antibodies) can reveal if the immune system is contributing to thyroid dysfunction.
The Importance of a Full Thyroid Panel
A complete thyroid panel, including Free T3, Free T4, Reverse T3, and thyroid antibodies, provides a more accurate picture of thyroid health. Functional medicine focuses on finding the root cause of thyroid symptoms rather than just relying on TSH levels. Addressing inflammation, nutrient deficiencies, and stress can help the body use thyroid hormones more efficiently.
When thyroid symptoms persist despite normal TSH, deeper testing is needed to uncover the real issue. Proper evaluation and a personalized approach can help restore energy, improve metabolism, and bring balance back to the body.