Testing for thyroid function has become controversial. For many years the conventional thyroid test has
measured thyroid stimulating hormone (TSH), the hormone excreted by the pituitary gland to stimulate the thyroid.
The theory was that high levels of TSH in the blood indicate a sluggish thyroid that needs a push from the master gland to
get its job done.
In this simplistic approach, the range of TSH levels that is considered “normal”
can be quite wide. Many labs in the US consider a TSH of 0.4–5.0 to be within normal range. Within this “normal”
range, many practitioners won't diagnose a thyroid problem like hypothyroidism even if it actually is struggling. Outside
this range many practitioners will diagnose thyroid disease and write a one-size-fits-all prescription for a synthetic thyroid
supplement, usually Synthroid, Levoxyl, or Levothyroid.
Our approach to the thyroid test
In publishing new clinical guidelines in 2002, the American Association of Clinical Endocrinologists fairly dramatically
formalized a reversal of its previous doctrine, establishing a narrower “normal” TSH margin of 0.3–3.04.
At Saylor Medical Group, we have used the TSH thyroid test for many years as a screener. And in our view, a woman’s
TSH level should ideally be less than 2.0 and she should also be free from hypothyroidism symptoms. If she
reports symptoms, or shows a TSH level greater than 2.0, she may have subclinical or clinical hypothyroidism.
For women with more pronounced hypothyroidism symptoms, we feel that the TSH test is inadequate because it doesn’t
tell us enough about the underlying problem. To do that, we need more detailed tests to show what the thyroid is producing
and what is available for the body to use.
The predominant product of the thyroid is T4 (thyroxine),
which is then converted by the liver into the usable form T3 (triiodothyronine). There are many causes of inadequate T4 production,
including adrenal stress, poor nutrition, and autoimmune thyroid disease. Similarly, many factors cause inadequate conversion
of T4 into T3, including lack of adequate nutrients and minerals and poor liver function.
are blood tests now that provide a complete picture of how well the thyroid produces T4, how much of the active form T3 is
created, how well the body converts and uses the T3, and whether there are significant anti-thyroid antibodies present.
Also important to a skilled practitioner is a woman’s medical history and physical examination, especially
by gathering information about her skin, eyes, hair, energy level, bowel habits, and body temperature.
In many cases a thyroid disorder is actually an indication of imbalance in some other body system. Adrenal Stress, for example, impairs thyroid function. Excess cortisol blocks the efficient conversion and peripheral cellular
use of the thyroid hormones at many levels. For this reason we often evaluate and, when appropriate, test saliva for adrenal
function in combination with thyroid testing. About 80% of the women we see and test has underfunctioning adrenals.
Testing saliva for progesterone levels during the luteal phase (second half) of the menstrual cycle may
also be of great value. If excess estrogen in relation to progesterone levels is found to be negatively impacting the thyroid,
gentle progesterone supplementation can be implemented. We have found that most women age 40 and beyond has insuffecient
levels of progesterone.