The Challenge of Defining 'Normal' Thyroid Function

If you're concerned about thyroid health, chances are good that you've probably already had the most common lab tests used to track thyroid function. Maybe you received what your physician described as a 'normal' test result in the past, but you're still concerned about a family history of thyroid problems, or you're experiencing a persistent pattern of symptoms that seem consistent with what you know about thyroid disorders.

Confused? Well, you're not the only one. At this very moment, a debate is raging in the thyroid health community over the way that common test results are interpreted. Specifically, there is a great deal of controversy over the test results that should be described as 'normal' -- and, due to the fact that each person's body is unique, whether a generic range of normal thyroid function can even be said to exist.

Recent Advances in Thyroid Tests Lead to Debate over How Results Should Be Interpreted

The good news is that the medical technology that is used to track and analyze thyroid function has been improved significantly in recent years. The most common laboratory tests that are now used to report thyroid health are now much more advanced than their predecessors, able to detect fluctuations in thyroid hormones with incredible sensitivity.

The not-so-good news is that there is still no clear consensus on how these more accurate results should be interpreted. Suddenly, many of the diagnostic categories that have been around for decades are no longer as applicable as they once were. Results that once fell into the 'normal' range are now being scrutinized more closely for clues to possible thyroid disorders.

'Normal' Thyroid Test Results -- and What They May Mean for Your Health

The most intense debate over thyroid lab test interpretations centers on the most common diagnostic procedure, the TSH test. This lab test measures the amount of thyroid-stimulating hormone in the blood, and it is the diagnostic tool that is most frequently used to screen patients for hypothyroidism and other common thyroid disorders.

When a TSH test is conducted, each patient's results are compared against a standard norm in order to determine whether the thyroid is functioning properly and emitting appropriate levels of thyroid hormone into the bloodstream. However, there is widespread disagreement over just what the standard norm that is used as a reference point should be.

Some physicians and scientists contend that the traditionally-defined norm of a reference point in the range of .5 to 5.0 should be upheld. In other words, those who defend this position believe that the long-established values used for interpreting TSH test results are still applicable.

However, on the other side of this debate is a growing group of doctors, medical associations, and patient advocacy groups who argue that this range is far too broad. This reform-oriented group suggests that the TSH test's reference range for 'normal' should be modified to .3-3.0. In other words, in this group's view, any patient whose TSH test results are less than .3 or greater than 3.0 should be referred for additional thyroid evaluation.

What to Do if Your Doctor Thinks You're 'Normal'…But You're Not So Sure

If you happen to be one of the millions of patients whose TSH results fall into the range of 3.0 to 5.0, your doctor may be one of the traditionalists who still regard this as a sign that your thyroid is functioning normally. If you are satisfied with this interpretation and you are not experiencing any additional symptoms, just be sure to remind your doctor to keep an eye on any potential thyroid concerns in the future.

However, if you fall into the 3.0-5.0 range on the TSH test and you continue to experience thyroid-related symptoms or other inexplicable health problems, it may be time to seek out a second opinion. A thyroid specialist or endocrinologist may be better equipped to answer your concerns in greater detail.

When it comes to thyroid health, it's important to trust your instincts. If your current physician isn't responsive to your concerns, it may be time to shop around a bit. Please check back each week for more of the news and information you need to achieve and maintain optimal thyroid health.

For Further Reading

• http://www.endocrineweb.com/tests.html

• http://thyroid.about.com/od/gettestedanddiagnosed/a/tshtestwars.htm

• http://www.ithyroid.com/thyroid_test_interpretation.htm