Thyroid Hormone Therapy
Thyroid hormones, primarily Triiodothyronine (T3) and Thyroxine (T4), are the key regulators of metabolism, and imbalances in these hormones can lead to wide array of symptoms. Abnormal levels of thyroid hormones can cause a wide array of symptoms both when levels are too high (hyperthyroidism) and when they are too low. Hyperthyroidism is less common, and should prompt urgent evaluation by a qualified physician as the diagnostic evaluation and treatment of hyperthyroidism are somewhat complicated. We deal primarily with patients that have hypothyroidism, in which levels of thyroid hormones are too low.
Typical symptoms of hypothyroidism include fatigue, weight gain, skin dryness, constipation, and sensitivity to cold. If you have symptoms of hypothyroidism, our treatment team will check the levels of thyroid hormones (T3 and T4) and thyroid stimulating hormone (TSH) in your blood. If your laboratory tests are consistent with hypothyroidism, we will prescribe an appropriate dose of supplemental thyroid hormone and frequently monitor and adjust your dose based on both laboratory assessment and through your ongoing feedback about how you feel.
Why Do You Check Tsh, T3 And T4?
TSH is a hormone that stimulates the thyroid gland to make T3 and T4. Checking for abnormal TSH levels is the most common initial screening test for thyroid disorders. T3 is the active form of thyroid hormone, but the majority of thyroid hormone circulating in the bloodstream is actually T4. T4 is a prohormone, which has minimal hormonal effects by itself but is converted to T3 at the site action. By checking TSH, T3, and T4, we can assess the overall balance of all 3 hormones. Treating hypothyroidism with supplemental T4 alone is usually adequate, although occasionally patients note improvement in symptoms with the addition of supplemental T3.
What If A Patient Has Symptoms Of Hypothyroidism But Their Thyroid Hormone Levels Are Within The “normal” Range?
Hypothyroidism is often under-treated because most physicians select doses of thyroid hormone in order to achieve laboratory values that fall within the “normal’ range. These “normal” values are based on population studies, but every individual is different and has a different optimal level of thyroid hormone in order for their bodies to function most effectively. It is essential to consider how a person feels, not just lab values, when developing a treatment plan. Unfortunately, the main symptoms of hypothyroidism are somewhat nonspecific and can also be caused by many other medical conditions or lifestyle factors. After identifying and correcting other potential causes, it may be reasonable to try a small dose of thyroid medication and look for improvement in symptoms. Of course in this situation, our goal would not be to overtreat and cause hyperthyroidism, however even minor adjustments in dosages of thyroid hormone or the addition of supplemental T3 may be harmless and help you feel better.