Thyroid Testing: Unreliable TSH Levels
40% of all Americans suffer from hypothyroidism yet only about 10% of the patients tested will be diagnosed.
- Dr. Broda O. Barnes M.D.,
Hypothyroidism: The Unsuspected Illness
What if the lab test used by many doctors to determine Hypothyrodism was inaccurate and unreliable? You might be thinking: "How could this be?" Sadly, its quite true. And its easy to find this confusing, I know I did.
Within the medical community there is a debate about how to measure and diagnose Hypothyroidism. While many doctors and Endocrinologists rely entirely on TSH Lab Tests, other doctors feel the TSH is unreliable and inaccurate (see references below). You are only as good as your information! So here is an overview of TSH lab work, and what many doctors feel is a better way to diagnose Hypothyroidism.
Why Thyroid Blood Tests Can Be Unreliable
According to Your Thyroid and How to Keep It Healthy, author Barry Durrant Peatfield explains why thyroid blood tests like TSH can be unreliable:
1. Blood tests measure hormone levels in the blood rather than tissue levels (which he feels is more important).
2. Blood tests do not measure cellular receptor hormone resistance.
3. Blood tests do not measure conversion block (some patients cannot convert their inactive T4 to active T3).
4. Thyroid tests do not account for adrenal insufficiency.
5. And, paradoxical low TSH may occur with a low thyroid function.
I have sadly come across very few doctors who can accept the fact that a normal, or low TSH, may still occur with a low thyroid... as a result of this test (TSH), thousands are denied treatment
– Barry Durrant Peatfield
If not the TSH, then what?
According to Dr. Jeffrey Dach, MD, the TSH test is an indirect measure of thyroid function and can be unreliable. A more accurate indicator of thyroid function is the free T3. Free T3 lab test together with the absence of any signs or symptoms of thyroid excess indicates...the correct dosage of natural thyroid medication.
More Reading
I've covered the basics but there are tons of great resources about why TSH is unreliable...
