So, how is it that hypothyroidism can be missed by today’s conventional medical system?
That’s because many doctors rely exclusively on the TSH test and do not order a full panel of thyroid blood tests to make the diagnosis. The TSH level is an indirect measure of only one kind of thyroid hormone sufficiency and does not correlate well with symptoms. A normal TSH level doesn’t rule out partial secondary hypothyroidism–where the problem is in the pituitary gland or the hypothalamus (brain) itself. This problem is more frequent than currently recognized. It is an often unrecognized cause of depression, obesity, high cholesterol, chronic fatigue, and fibromyalgia. The current practice of excluding a thyroid hormone problem on the basis of a”normal” TSH is scientifically indefensible. A large number of things can go wrong with thyroid hormone production and effectiveness and yet not show up on a TSH test.
The best blood tests for thyroid hormone sufficiency are the levels of the actual free thyroid hormones in the serum: free T4 and free T3 as well as RT3. Also, thyroid antibodies should be checked as part of a thorough evaluation. A physician should be concerned when these are below the mid-point of their reference ranges in a symptomatic patient, and especially concerned when they are in the lower third or outside of their population ranges. However, even the free serum hormone levels cannot tell the whole story. Human physiology is much more complicated than that. There are many mechanisms by which a relative resistance to thyroid hormones can occur.
Although many conventional physicians would argue otherwise, the fact is that the thyroid blood tests may be in the reference range even though there is a low thyroid condition. In recognition of this problem the American Association of Clinical Endocrinologists recommended that the normal range for the TSH test be changed to 0.3 up to 3.04 mIU/L. The National Academy of Clinical Biochemistry wants to change them again and says “In the future, the upper limit of the serum TSH reference range will be reduced to 2.5 mIU/L and “a serum TSH result between 0.5 and 2.0 mIU/L is generally considered the therapeutic target for primary hypothyroidism.”
Once the diagnosis is made based on history, physical examination and proper interpretation of lab testing, the next step is a therapeutic trial of thyroid hormone. In the best tradition of clinical medicine, a physician should prescribe thyroid hormones for persons whose symptoms, physical signs, and/or blood tests indicate that they may have inadequate thyroid hormone effects for optimal health and quality of life. If they do not need the thyroid supplementation, they will need to have their adrenal glands evaluated with a salivary cortisol test. Thyroid optimization for those who need it improves mood, energy, and alertness. It reduces risk of a heart attack, helps with weight loss, and lowers cholesterol levels.
Dr. Randy Lundell, DO