It has been known for the last 50 years that Thyroid Function Tests are not reliable and that people with perfect blood tests could have advanced hypothyroidism.
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Myth #1: The TSH (Thyroid Stimulating Hormone) blood test is the only way to diagnose hypothyroidism/low thyroid.
Facts: First, there is no perfect test in medicine?not the TSH or any other. Second, nearly a century before the TSH test was developed, doctors made the diagnosis of hypothyroidism without any tests at all. They listened to their patients and examined them. Since then, there have been many tests that have been blindly followed until they proved to be unreliable and were discarded.
To this day, there are at least three types of hypothyroidism for which the TSH test does not even test. The TSH is not a useful test for hypothyroidism caused by dysfunction of the pituitary gland or of the hypothalamus (part of the brain,) or for hypothyroidism caused by "tissue resistance" to the effects of thyroid hormone.
My conclusion: The TSH test can miss the diagnosis of hypothy-
roidism. To most accurately identify hypothyroidism, I start with the approach that has worked for over a century. I listen to the patient and look for evidence of low thyroid function. If the patient appears hypothyroid, I order blood tests including the TSH, but I also (1) check basal body temperature,1 and (2) check the urine thyroid hormone levels.2 I then interpret all test results in the context of the
individual patient.
Myth #2: Normalizing the TSH (Thyroid Stimulating Hormone) blood test is the best way to treat hypothyroidism.
Fact:Many studies have shown adjusting thyroid doses to normalize the TSH blood test leaves many patients with symptoms of low thyroid. World-renowned thyroid specialist, Sir Anthony Toft, MD, discussed this sad fact in 2002. In a speech to the British Endocrine Society, Dr. Toft reviewed some of the evidence that demonstrated that the modern TSH-centered approach was ineffective. He concluded, "...the treatment of hypothyroidism is about to come full circle"?going back to the approach that worked so well before all of our modern tests and treatments were invented.3
My conclusion: Using the patient as my guide, I focus on reversing the signs and symptoms of low thyroid function while avoiding side effects or signs of thyroid excess. When the TSH is normal but the patient continues to be symptomatic, I prefer to err on the side of treating the patient?not normalizing the blood test.
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www.thyroid-info.com/topdrs/