For the last forty or so years, the TSH lab test has been used to diagnose thyroid conditions. However, many people and doctors do not know that the TSH test is unreliable! A person can have what is considered “normal” TSH, but still be hypothyroid. This was the case for me and many others. For the first 35 years of my life, I lived with undiagnosed Hypothyroidism because of normal TSH. Learn more about TSH and other test options.
Its easy to find this confusing, I know I did. Frequently, I meet people or people write me on my blog and say “I feel so many Hypothyroidism symptoms but my TSH is ‘normal’ so my doctor said I am fine.” The first most important message to understand is that some doctors rely entirely on TSH, but many doctors feel TSH can be inaccurate. Especially related to pregnancy and child birth when the pituitary gland can be damaged, affecting TSH, as explained by Sheehan’s Syndrome. Is it coincidence or not that Hypothyroidism affects women primarily more than men?
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
Further, in Dr. Broda Barnes pioneering book Hypothyroidism The Unexpected Illness he wrote that would be the ideal for [hypothyroidism] is not even possible. What we ideally need to measure is the amount of thyroid hormone on the inside of each cell in the body. Barnes goes on to say that it is obvious, of course, why such a test is impossible.
As you can see, within the medical community there is a debate about TSH and how to measure and diagnose Hypothyroidism. 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 TSH Lab 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:
- It measures hormone levels in the blood, rather than tissue levels which he feels is more important.
- It does not measure cellular receptor hormone resistance.
- It does not measure conversion block (some patients cannot convert their inactive T4 to active T3).
- It does not gauge adrenal fatigue.
- And, paradoxically, a low TSH may occur with a low thyroid function.
More Reliable Testing
According to Dr. Jeffrey Dach, MD, and Dr. Broda Barnes the more accurate indicators of thyroid function are the free T3, body temperature and symptoms. The Free T3 lab test together with the absence of any signs or symptoms of thyroid excess indicates the correct dosage of natural thyroid medication. Read about how to diagnose hypothyroidism.