We always talk about addressing the underlying causes of disease and dysfunction and not simply chasing off the symptoms. When it comes to thyroid health there are many variables that come into play. Deficiency of iodine is now becoming a commonly known contributor to thyroid dysfunction as is bromide and fluoride. Another lesser known contributor is Iron. In the article below written by the Designs for Health team they explain how low iron levels can play a role in poor thyroid function and also talk about addressing the underlying cause. I think you can go one step further and also ask yourself "why are my iron levels low?" A lot of the time we find that a deficiency in HCl is the cause of this as a deficiency in HCl makes you unable to absorb a lot of the nutrients you eat including iron and B12 as an example. This is something we learnt from Charles Poliquin and DR Jonathan Wright.
"These days it seems like the waiting rooms of functional and conventional medical practices alike are filled with patients anxious to get help for what they’re convinced is hypothyroidism. Desperate to do something to relieve their unpleasant and sometimes debilitating symptoms, they want the full thyroid panels they’ve read about online during their frantic searches to help themselves: TSH, total and free T3 and T4, reverse T3, TPO, and thyroid antibodies. And certainly, when the numbers and/or the preponderance of symptoms indicate a sluggish thyroid, treatment with dessicated thyroid or thyroid hormone may be warranted. However, even more important is to try and identify why the thyroid is not generating adequate hormones, or why the tissue-level conversion of T4 to T3 is not happening optimally. After all, even if a patient feels better upon taking oral thyroid hormone, this does nothing to address the underlying cause of dysfunction, thereby leaving the dysfunction to continue and become more severe."