Logic dictates that if the most common cause of hypothyroidism is from an autoimmune mechanism, then the first test ran on all newly diagnosed hypothyroid patients would be a thyroid antibody test. Well logic doesn't always reign supreme and in many cases Hashimoto's Autoimmune thyroid patients go undiagnosed and just given the standard thyroid replacement treatment. I am going to explore the most likely reasons this occurs.
The first and foremost reason most thyroid patients will never have their antibody levels checked is because the treatment protocol does not change based on the mechanism. Most doctors are going to give you synthetic thyroid replacement hormones, intermittently check your TSH, and call it a day. If you continue to suffer with the same symptoms as before they will be attributed to some other ailment, usually depression or anxiety, and be treated accordingly.
The second reason for the failure to order antibody tests, is a branch off of the first reason. Since the treatment is not going to be dictated based off the antibody results (although it should), then running the test becomes "medical waste" in the eyes of the insurance companies. The payment for a test that will not alter the course of treatment is in a way wasteful, but the real waste is in ignoring the underlying cause of the problem and leaving the patient to suffer. Many times patients are mocked and scorned for suggesting a test or treatment that is a bit outside of the tight little box Hashimoto's patients are placed in.
Having no alternative treatment plan for Autoimmune thyroid, and the resultant medical waste of a test ordered but that has no bearing on the patients treatment are the two main reasons many Hashimoto's patients go undiagnosed and ignored in the system.
Determining that hypothyroidism is from an immune mechanism, IS important, and should absolutely be managed in more comprehensive way, not only including some type of replacement hormone, but it should also include management of the immune systems destruction of the gland itself. A more comprehensive approach gives the patient a better chance to feel and function normally.