Most conventional doctors rely solely on the TSH test -- the thyroid stimulating hormone blood test -- to diagnose and manage thyroid conditions. The test measures a pituitary hormone, and is considered by many conventional physicians to be the best test -- they call it the "gold standard" -- for evaluating thyroid function. For those doctors, if your TSH test result falls within the reference range, then your thyroid is "normal."
The challenge? For five years, various groups within the endocrinology community have disagreed about the TSH test's reference range. One group favors a range of 0.5 to 5.0, while another group believes that the recommended new range of 0.3 to 3.0 should be adopted. TSH levels above the top of the range are considered evidence of hypothyroidism, an underactive thyroid.
The number of Americans whose TSH levels fall in that limbo between 3.0 and 5.0 -- which is "normal" to some doctors, and hypothyroid to others -- is estimated to be in the millions. That means some people with a TSH of, for example 4.0, will have doctors who treat them for hypothyroidism. Other doctors will tell a patient with a TSH of 4.0 that "your thyroid is normal."
The solution? Always ask for the numbers. If you are told that your thyroid is normal, ask for the specific test names and results, and the reference range being used to make that decision. And, if you are experiencing symptoms, your TSH falls into that 3.0 to 5.0 limbo, and you have a doctor who believes that is normal and won't diagnose or treat you, it's time for a new doctor.