For all the hypothyroidism patients struggling with symptoms but doctors insist their thyroid lab results are normal, normal, NORMAL, this is for you.

Written by Hugh Melnick, MD

Hypothyroidism is a common condition that is frequently undiagnosed and is often inadequately treated. Its symptoms are many, diverse and often prevent people from leading productive and fulfilling lives. As a result, there are many people who, frustrated by the failure of the medical establishment to provide adequate treatment for them to have symptomatic relief, do a deep dive on hypothyroidism in order to become educated healthcare consumers. 

There is no doubt that many individuals with hypothyroidism whose symptoms persist despite “ideal blood test levels” have lost confidence in their doctors and feel that they need to take an active role in managing their own medical issues. Having access to their own lab test results from a patient portal is a great way to do this. However, if you are inclined to do so, you must be aware that interpreting thyroid blood test results is not as simple as it may appear to be. Errors in the interpretation of thyroid blood test results are one of the two major causes of the failure to correctly diagnose hypothyroidism. The other major cause of misdiagnosing hypothyroidism is the failure of physicians to pay attention to their patient’s symptoms and to recognize the relationship of symptoms with low thyroid function.

When you receive your thyroid lab results, next to each blood test result is its Reference Range. The reference range is used by physicians to interpret blood test results. Formerly called the Normal Range and still referred to by many doctors as such, there is a great deal of confusion regarding the meaning of the word “normal”. In the context of reference ranges, “normal” is actually a statistical term meaning a type of average of the results of 95% of the people tested. It has nothing to do with the person’s state of health! Yet most physicians misinterpret the term “normal” as the equivalent of being healthy. The often used phrase “within normal limits” incorrectly implies that every person whose thyroid blood test results fall within the reference range does not have hypothyroidism, which is obviously not the case.

Symptomatic people with the classic symptoms of hypothyroidism very often have thyroid hormone levels in the low end of the reference range. Yet they are misdiagnosed because their blood test results were interpreted as being “normal” because they are within the reference range.

That is precisely the reason for the need to factor in a person’s clinical symptoms when interpreting their blood tests results. Blood tests results are just numbers and cannot be interpreted in a vacuum.

HYPOTHYROIDISM 101

Now that you understand the issues that you must keep in mind when you view your thyroid lab results, the first thing to do is to make sure that the following blood tests have been performed. I have listed them in descending order according to their diagnostic significance.

Here are a few important facts to keep in mind about blood test results.

• Blood levels and blood test results normally fluctuate, symptoms do not.
• Never base thyroid medication dose exclusively on blood test levels of TSH, T3 or T4.
• Do not use the laboratory reference range on its own to make a diagnosis of hypothyroidism or hyperthyroidism without considering a person’s symptoms.
• Blood test results must make sense and must fit into the context of a patient’s clinical picture.

REQUIRED THYROID BLOOD TESTS

Free T3

Total T3

Anti TPO Antibodies 

Anti TGB Antibodies

Free T4

Reverse T3

TSH

T3

Free T3 (fT3) is the most biologically potent thyroid hormone, hence it is the most important one to test. T3 enters each and every cell in the body and supplies energy for proper cellular function. It is important to remember that although the correlation between T3 levels in blood and the symptoms of hypothyroidism is high, the correlation is not 100%. That is why it is important to go with a person’s symptoms over their blood test results when diagnosing and treating hypothyroidism.

Although most people require NDT doses between 180-360 mg per day to be symptom free, some people require even higher doses of thyroid medication, above 360mg per day, in order to obtain complete symptomatic relief. This will drive their blood levels well above the upper limit of the reference range. Being above the reference does not necessarily mean that a person is hyperthyroid, unless they have the typical symptoms of hyperthyroidism. As long as the resting heart rate stays below 90 beats per minute continue with the dose of thyroid medication that relieves symptoms. Remember to treat the patient and not the numbers!

In my experience, the most significant laboratory evidence supporting a diagnosis of hypothyroidism is when free T3 levels are below 3.5 and the total T3 levels are below 125. These values are well within the reference range, yet they correlate fairly well with the symptoms of hypothyroidism in many people. 

These values are not printed on any laboratory report nor are they found in any textbook. They are called “functional levels” and are determined by each physician who has treated a large number of symptomatic hypothyroid individuals and has correlated their laboratory results with their symptoms. These numbers are the true “normal values.” Remember them.

When patients are taking natural desiccated thyroid medication NDT, it is quite normal to have T3 levels that are above the top of the reference range. In many cases, it is actually necessary to have fT3 levels up to 7.5 to obtain symptomatic relief. Ideally, blood specimens should be drawn about 6-8 hours after the first dose of the day for people taking NDT. The most common cause of abnormally high blood test results is that a person’s blood specimen was obtained too close to the time that they took their medication. This often occurs when a person on any thyroid medication containing T3 visits their medical doctor in the morning, and has their “routine” blood work drawn. There are always alarming phone calls from the doctor’s office about over medication and immediately stopping thyroid medication. 

The most important thing to remember is that if you are feeling well, the dose of your thyroid medication is ideal and should not be changed. Never change your dosage because of a blood test result. Common sense must prevail. As long as a person’s resting heart rate stays below 90 beats per minute, they are not taking too much thyroid medication. 

Anti-Thyroid Antibodies

Everyone having the symptoms of hypothyroidism must be tested for the thyroid autoimmune condition called Hashimoto’s Thyroiditis with blood tests to detect the presence of anti-TPO (Thyroid Peroxidase) and anti-TGB (Thyroglobulin) antibodies.

Normally, a person should not have detectable antithyroid antibodies in their blood. The presence of even a trace amount of anti-thyroid antibodies strongly suggests that Hashimoto’s is the root cause of a person’s hypothyroidism. It is important to differentiate Hashimoto’s from other causes of hypothyroidism since dietary considerations, as well as thyroid medicine, are essential to treat this condition successfully. I go into more detail on the treatment of Hashimoto’s thyroiditis in this article: Hashimoto’s thyroiditis: a case of immunological mistaken identity.

When tested, a level of antibody as low as 1 is positive in a symptomatic individual. The presence of an antithyroid antibody is more important than its numerical value. A person with a level of 1 may actually be more symptomatic than a person who has a level of 300!  

The major problem is that most clinical laboratories do not do adequate antibody testing. Most labs report results only above 9. They do not analyze a blood specimen for very low antibody levels and report results as an antibody level of less than 9 (<9) as being normal. Consequently, people with antibodies between 8 and 1, who are likely to have Hashimoto’s, go undiagnosed. As far as I know, Quest is the only commercial clinical laboratory that reports antibody results properly. When you look at your lab results, be sure that you have results for both antibody tests and that the results are reported in a way that the lowest levels of antibodies have been measured.

FREE T4

Free T4 (fT4) is a weak thyroid hormone under normal circumstances, but when too much T4 is produced abnormally by the body, as in true hyperthyroidism (Graves Disease), or when too much thyroid medication is taken or accumulates in the body (known as pooling), a person will experience symptoms such as a rapid heart beat, tremor, anxiety and excessive sweating. It is also not unusual for hyper symptoms to occur intermittently in people having Hashimoto’s thyroiditis. High levels of free T4, over 2.1, are meaningful only when accompanied by the typical symptoms of  hyperthyroidism. In people who are taking thyroid medication and who  do not have hyper symptoms, fT4 levels above the reference range should be ignored and the dose of thyroid medication should not be reduced.

Treat the patient, not the numbers.

REVERSE T3

T3 is a biologically inactive molecular mirror image of active T3. As such, elevated levels of rT3 decreases the amount of energy delivered to the body’s cells. Less cellular energy causes a reduction in cellular function, ultimately producing the symptoms of hypothyroidism. The two T3’s are like two bullets, one loaded, one blank, but both looking exactly alike. The likelihood of hitting a target depends on the ratio of live rounds to blanks. The more live rounds in the gun, the greater the chance of hitting a target. The less rT3, the more cellular energy and the less symptoms of hypothyroidism. 

Since rT3 is made from high levels of T4, the way to reduce the  level of rT3 is to eliminate all T4 containing thyroid medications, both Synthroid and NDT. A pure T3 protocol (Liothyronine or Cytomel ) is then used to virtually eliminate all Reverse T3. I often see high rT3 levels (above 30) in patients requiring relatively high doses of T4 medication but who are not experiencing relief from their symptoms. The pure T3 protocol works well for these patients when the correct dose of T3 is reached.

Do not use blood tests to monitor patients on the pure T3 protocol. The results will freak you out, but are not unexpected. The T3 levels are “off the charts” high, and, as expected, reverse T3 and T4 levels are near zero. Manage dosage of T3 by only a person’s symptoms. 

Nevertheless, most patients who don’t do well on other thyroid medications, Synthetic T4 and NDT, usually feel much better when they arrive at their ideal dose of pure T3. Most people feel symptom free at doses between 50mcg-250mcg of T3 per day. The bottom line when dealing with hypothyroidism is not to “miss the forest for the  trees” by paying more attention to a patient’s blood test results than  the patient’s symptoms. 

TSH

I think that by now you suspect that I am not a great fan of the TSH test. The TSH level is within the reference range in at least 40% of people who have the common symptoms of hypothyroidism. Used as a screening test for hypothyroidism, as it is by most physicians, clinically hypothyroid individuals are too frequently misdiagnosed as having normal thyroid function. As a result, they are denied treatment that can affect the quality and duration of their lives. 

Hypothyroidism, when undiagnosed or inadequately treated, has detrimental effects on the quality of life, health and longevity. Because of this, screening for this condition must be more effective than it currently is today and has been for the past 50 years. In order to increase its effectiveness by “casting a wider net”, hypothyroidism screening should include testing for T3 and antithyroid antibody levels to more accurately identify hypothyroid individuals. 

There are potentially serious consequences resulting from the failure to diagnose and adequately treat hypothyroidism. Studies demonstrate a higher risk of heart and of Alzheimer’s diseases in people having hypothyroidism. Furthermore, many psychiatric and behavioral conditions such as depression, bipolar disorder, learning disabilities, panic attacks and insomnia are ultimately linked to untreated hypothyroidism. If properly diagnosed and treated, there would be a tremendous improvement in the quality of life of effected individuals. 

In the areas of fertility and maternal-fetal medicine, undiagnosed hypothyroidism may have profound ill effects. I see case after case of subclinical hypothyroidism in my fertility clinic. Young women with Hashimoto’s thyroiditis have a high rate of premature menopause which has an irreversible effect on a young woman’s fertility. These young women, once identified, can preserve their future fertility by freezing their eggs until the time is right for them to attempt conception.

There is a possible link between untreated maternal hypothyroidism and autism, which is just one of several major complications of pregnancy associated with undiagnosed and untreated maternal hypothyroidism. Many complications of pregnancy such as miscarriage, premature delivery, and stillbirth have been associated with hypothyroidism and can be prevented by treatment with thyroid medication during pregnancy. Not only is thyroid medication during pregnancy safe for both mother and her fetus, it is mandatory to insure the best outcome for both mother and baby.

The second reason that the TSH test causes serious problems for thyroid patients is that most endocrinologists determine the dose of a patient’s thyroid medication dose based upon restoring their TSH levels to “normal” levels. Data demonstrates that by restoring TSH levels to “normal” levels will only relieve symptoms in 60-75% of patients with hypothyroidism. This does not work because intracellular T3 levels, reflected by a person’s symptoms and not by the levels of TSH in the blood, determine the adequacy of thyroid function. Patients must be evaluated clinically for the resolution of their symptoms, which is the most reliable guide to the adequacy of intracellular T3 levels and of thyroid medication dosage.

Another TSH issue is “over suppression of TSH”. When you hear those words, grab your coat and find the nearest exit to make your escape from that doctor’s office as fast as you can! All too often a misguided doctor sees an asymptomatic thyroid patient having a very low TSH level and, on that basis alone, tells a patient that they are “over suppressed” and are hyperthyroid because they are taking too much thyroid medication. In fact, very low levels of TSH are normal for patients on thyroid medication. The doctor then reduces or stops thyroid medication and guess what happens? The patient becomes hypothyroid again. Remember, if the free T4 level is less than 2.0 the patient is not hyperthyroid.

CONCLUSION

The main take away message of this article on blood testing is that doing blood work is not essential to the successful diagnosis and treatment of hypothyroid. A person’s symptoms are the key to diagnosing and treating hypothyroidism successfully. If you believe that blood work results will be helpful to dealing with your personal thyroid issues, or confirming your diagnosis, be my guest and go ahead and do them. At least you will now be able to interpret your blood test results correctly and have a better understanding of their significance. 

Although most endocrinologists trained after the mid 1970’s consider my position favoring the clinical diagnosis of hypothyroidism and its treatment with natural desiccated thyroid to be nothing less than heresy, I have seen that over reliance on blood test results is the most common cause of missing the diagnosis of hypothyroidism in obviously hypothyroid individuals. Furthermore, basing treatment of hypothyroidism upon blood work inevitably results in treatment with the wrong thyroid medication or an inadequate dose being prescribed. In my humble opinion, the only reason to do blood work is to define the root cause of a person’s symptoms, which leads to better treatment in order to obtain symptomatic relief.

I would like to leave you with one final suggestion. If you do have hypothyroidism please find a physician who listens to your symptoms, understands their relevance and bases your treatment upon relieving your symptoms. Do not treat yourself! “ A doctor who treats himself has a fool for a patient.”

About Hugh Melnick, MD

Dr. Hugh Melnick is a reproductive endocrinologist who has been treating patients with hormonal and fertility problems since 1976. In 1983, Dr. Melnick founded Advanced Fertility Services, which was the first free standing In Vitro Fertilization Center in New York City and is still its medical director. Dr. Melnick’s vast clinical experience along with his own personal experience with hypothyroidism has enabled him to develop a unique approach to the diagnosis and treatment of hypothyroidism. During his many years of clinical practice, he has recognized how hypothyroidism can adversely affect every part of the human body which inevitably interferes with a productive and enjoyable quality of life. In addition to fertility, Dr. Melnick specializes in the treatment of hypothyroidism in women and men of all ages.

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