The interpretation of any clinical laboratory test involves an important concept in comparing the patient's results to the test's "reference range." (It's also commonly called the "normal range" but today reference range is considered a more descriptive term'

Some tests provide a simple yes or no answer. Was the culture positive for strep. throat? Did the test find antibodies to a virus that indicates an infection?

But for many more tests, the meaning of the results depends on their context. A typical lab report will have your results, followed by a 'normal' or 'reference range' For example, your results for a thyroid-stimulating hormone (TSH) test might look something like: 2.0 m-IU/L, ref range 0.5 - 5.0 m-IU/L. Such a test result indicate that it falls within the "normal" range.

How was the 'reference range' established? The short answer is: by testing a large number of apparently healthy people and observing what appears to be "normal" for them.

The first step in determining a given reference range is to define the population to which the reference range will apply, for example, healthy females between 20 and 30 years old. A large number of individuals from this category would be tested for a specific laboratory test. The results would be averaged and a range (plus or minus 2 standard deviations of the average) of normal values would be established.

The term "reference range" is preferred over "normal range" because the reference population can be clearly defined. Rather than implying that the test results are being compared with some ill-defined concept of "normal", the reference range means the results are being considered in the most relevant context. When you examine test results from different populations, you quickly discover that what is "normal" for one group is not necessarily normal for another group. For example, pregnancy changes many aspects of the body's chemistry; so pregnant women have their own set of reference ranges.

This is the problem - we Thyroidians and CFS-ME-FM folk along with others with chronic illnesses are being tested against a 'reference range' that was established for a group of 'normal' people. People who were healthy at that time and didn't have any health issues. A new 'reference range' must be established especially for sufferers showing the kind of unexplained symptoms which most of us are presenting with.

To stop all the confusion and mis-diagnosis (or NO diagnosis in thousands of cases) that come from lack of correct interpretation, everybody should have their thyroid levels checked automatically to see what their 'normal' reference range is when they are, say a healthy18 years old. THEN, when they present with unexplained symptoms, blood tests would then be a fairer comparison.

By not being correctly diagnosed and treated if we have a low metabolism from our thyroid winding down have other effects. One is that our urinary system runs down, so that we are more likely to get infections, and less able to fight cancer; our adrenals which fight stress also weaken, which not only worsens the effect of low thyroid, but prevents any treatment working properly.

Never accept that if your tests fall within the so-called 'normal' reference ranges that your health is 'normal'. Insist that your doctor gives you a thorough clinical examination and addresses all the symptoms you are presenting with. If any of your tests are out of range, ask him to refer you to an endocrinologist for a second opinion.