Why Thyroid Tests Can Be Tricky

Thyroid lab testsWe often hear that thyroid disease is easy to diagnose and simple to treat. All you need is a simple blood test and it doesn’t matter what the other numbers are because hypothyroidism treatment is the same no matter what the cause is.

Then why do so many people remain undiagnosed, undertreated and mistreated? The reality is that hypothyroidism is more complicated than that.

The best way to eliminate hypothyroid symptoms is to get a proper diagnosis to correct the underlying problem

The most common cause why so many people struggle to get diagnosed is that there is NO single thyroid test available to make a proper hypothyroidism diagnosis.

Another very common cause is  that thyroid problems seldom come alone and other hormonal imbalances are often present – especially adrenal dysfunction, low progesterone, high estrogen or estrogen dominance in women or low testosterone in men.

Choosing right tests helps to identify the problem and is the most important first step because without a proper diagnosis there is no successful treatment.

Why TSH Test Is NOT Your Best Option

While the TSH test is the ONLY test that is used by medical doctors to screen for hypothyroidism it is not a reliable indicator to diagnose hypothyroidism. Here is why:

1. Most doctors do not order the right thyroid tests

I know you may be very surprised to hear this. After all, we trust and rely in our doctors. How do doctors NOT know what thyroid tests to order?

Following the official hypothyroidism treatment guidelines most conventional doctors make a diagnosis based solely on TSH (Thyroid Stimulating Hormone) test or a combination of TSH and T4 thyroid hormone testing.

In most cases these are the ONLY tests that the doctors order when they suspect hypothyroidism. However, for many people the results come back “normal” even if they have hypothyroid symptoms. In fact, running an complete thyroid panel that includes tests for:

  • TSH
  • Total and free T3 and T4 thyroid hormones
  • TPO and Tg thyroid antibodies
  • T3 uptake
  • Reverse T3

can give you a better understanding if your thyroid is functioning properly. Otherwise if you rely only on the TSH test your hypothyroidism can remain undiagnosed, undertreated and mistreated in many people.

2. TSH normal range is too wide

Different countries have their own treatment guidelines for hypothyroidism and a normal thyroid levels for the clinical laboratory standards. Outdated and too broad TSH normal range is still a common practice in medical labs in England, Canada, Germany and many other countries.

When your doctor receives your thyroid test results from the lab he also gets recommended normal thyroid levels for all measured parameters. If the lab uses too wide of a TSH normal range there is a high probability that a proper diagnosis cannot be made.

In fall of 2002 American Association of Clinical Endocrinologists (AACE) issued new guidelines for TSH normal range and recommended to change it from 0.5-5.0 to 0.3-3.0. However, many doctors are still unaware about these changes and use an outdated normal thyroid levels for hypothyroidism assessments.

According to AACE estimates, if doctors would follow the new guidelines the number of people who have abnormal thyroid function could double. This means that about 20% of US population could be hypothyroid.

new TSH normal reference range

3. TSH normal range is relative

One of the biggest problems with TSH testing is that being in the normal range does not guarantee that you will be free from hypothyroid symptoms. There are two main reasons why the symptoms may persist:

3.1. How the normal reference ranges are established by the labs

You may be very surprised to discover  that the normal thyroid levels are established by taking an average of all test results that were performed by the lab during the last year.  Basically it means that the guidelines for diagnosing hypothyroidism are based on test results of people in your area who are not healthy and show some degree of poor thyroid health. Some of them are already taking thyroid medication or have undiagnosed thyroid conditions. Thus being in the TSH “normal” range probably means you have some medical problems.

Here are some excerpts from the Laboratory Medicine Practice Guidelines: Laboratory Support for the Diagnosis and Monitoring of Thyroid Disease issued by The National Academy of Clinical Biochemistry which is a part of the Academy of the American Association for Clinical Chemistry (AACC):

TSH euthyroid reference range

3.2. Normal vs Optimal Thyroid Test Results

The TSH normal reference range refers to a statistical equation and does not reflect the therapeutic range that would be the best for a patient. Based on how the normal thyroid levels are established you are most likely to have some medical problems if your labs fit this value. But what you really want is the optimal health rather than average or normal.

Normal lab test results are not the same as optimal

Lab test reports provide your physician only with high and low values of the normal thyroid levels. Unfortunately, too often doctors try to bring the patient into the normal lab range rather than optimal.

4. Many types of thyroid dysfunctions cannot be diagnosed using the TSH test alone

About 95% of hypothyroidism is due to an autoimmune condition called Hashimoto’s disease that initially starts with an inflammation of the thyroid gland. Hashimoto’s can take years to develop and gradually progress to hypothyroidism. High TPO and Tg antibodies are early indicators of an active autoimmune process. However, Hashimoto’s disease cannot be diagnosed using the standard thyroid testing that includes TSH only or TSH and T4 tests.

Thyroid receptors are present in all tissues and organs of human body and need adequate levels of thyroid hormones to function properly. Another problem with thyroid testing is that all thyroid tests measure hormones in the blood. Test results do not give information about the amount of thyroid hormone that enters the cells and is being used by your cells. You can have perfect thyroid test results and plenty of thyroid hormones in your blood but be hypothyroid on a cellular level.

There are a number of physiological and dietary factors that can block your thyroid hormones in your bloodstream and at the cellular level. Most common factors that prevent thyroid hormones from entering the cells are:

  • Suboptimal cortisol levels
  • Estrogen dominance when too much thyroid hormone is bound to thyroid binding globulin (TBG)
  • Anemias

5. There are other thyroid unrelated factors that can affect TSH

TSH test results can be influenced by a number of external factors that are not directly related to thyroid function and the thyroid gland itself. All hormones fluctuate and tests give information about thyroid levels only at one single moment in time. Any of the following factors can influence your thyroid hormone levels:

  • Stress
  • Aging
  • Infection
  • Blood Sugar
  • Hormonal imbalances
  • Digestive issues

For example, your thyroid hormones can be affected by estrogen and progesterone that are secreted in a woman’s body cyclically. If a woman takes her thyroid test in the middle of her cycle when estrogen production is at its maximum or at the day 20 of her cycle when the progesterone production peaks she can have a different outcome of her thyroid tests.

6. TSH does not explain why you are hypothyroid

According to Dr. Datis Kharrazian, there are 22 thyroid dysfunctions that can result in hypothyroidism. Standard thyroid tests cannot pick up most of them and extended thyroid testing is required to establish why you are hypothyroid.

Furthermore, using thyroid tests alone doctors often cannot identify the cause of hypothyroidism. For example, iodine deficiency is one of most common causes of hypothyroidism in developing countries and areas with iodine depleted soils. The TSH test can only confirm that a person has hypothyroidism, but without iodine test there is no way to establish that hypothyroidism was caused by iodine deficiency.

To get a better idea about problems with modern lab testing and how it can affect your diagnosis just watch this 4:57 minutes video from Dr. Bryan Walsh

More videos from Dr. Bryan Walsh

There Is NO Single Best Test For Hypothyroidism

Tests are designed to diagnose a disease and do not do a good job in establishing a diagnosis in borderline cases, on early stages of thyroid disease and people with unexplained symptoms when most of them are subtle and non-specific. By the time thyroid tests show any abnormalities you may have already developed full-blown hypothyroidism and may require thyroid medication to correct it. This is the reason why standard lab ranges are referred as pathological or disease ranges.

As I previously mentioned that the TSH test alone is not a reliable diagnostic criteria for hypothyroidism. It also does not provide the information about the cause of thyroid dysfunction that is necessary to establish for a successful hypothyroidism treatment.

While extended thyroid panel can provide you with a very useful insight about your thyroid hormones and other factors related to thyroid health, it fails to give you the most important piece of information you need to know: how much thyroid hormone enters into your cells and is actually being used by your cells.

At the moment there is no testing that can provide accurate and reliable information about thyroid hormone levels on the cellular levels and probably won’t have these lab test available any time soon. There are some private labs that do saliva testing for thyroid hormones but mainstream labs do not offer these type of tests.

One of the very common indicators of low metabolism and possible hypothyroidism are hypothyroid symptoms such as intolerance to cold, feeling cold all the time when other people are not and having cold hands and feet. If you experience some of these symptoms  measuring your Basal Metabolic Rate can give you first insights about your metabolic state.

The Basal Metabolic Rate test measures the amount of oxygen that you consume when your body is completely at rest which is your basal state. Your rate of oxygen consumption can then be used to determine your metabolism and thyroid function.

Basal metabolic rateHowever, this test can be misguiding and unreliable if you do not know how to do it correctly. Your truly basal state is at the morning right after you wake up. By simply measuring your temperature first thing in the morning you can determine if your thyroid functions properly or you are hypothyroid.

Thyroid is not the ONLY factor that affects your body temperature.

For example, you can have fever as high as a 104 to 105 degree because of a cold or your temperature can be low due to adrenal fatigue.  Typical body temperatures range from 95 to 97 degrees in elderly people if no infection is present.

Most alternative practitioners advise to measure your temperature only in the morning after awakening which is actually not the only way to assess your metabolic state. I found that Dr. Bruce Rind’s Metabolic Temperature Graph™ works better than measuring your Basal Metabolic Rate for determining if you have thyroid and/or adrenal problem as well as for monitoring your progress of recovery.

According to Dr. Rind, you take your body temperature 3 times during the day 3 hours apart. You should measure your temperature orally using a digital oral thermometer such as Lumiscope Digital Thermometer that is inexpensive, does not contain mercury and provides accurate results. So if you wake up at 7 am you take temperature at 10 am, 1 pm and 4 pm. Do not take your temperature right after you have exercised, have eaten or under stress. Wait for at least 20 minutes or you will have inaccurate results.

Determine your daily average for at least 5-7 days, plot it on a graph and see if your temperature has a stable or erratic pattern. Stable but low body temperature indicates hypothyroidism while unstable and low temperature indicates both adrenal fatigue AND hypothyroidism.

What To Do If You Have Hypothyroid Symptoms

Many people have symptoms because they suffer from thyroid imbalances that are not advanced enough to be picked up by the standard tests. Since there is no single best test for hypothyroidism, using a combination of markers such as extended thyroid testing, measuring your body temperature and evaluating your symptoms brings the best results and significantly increases your chances to get a proper diagnosis.

7 Steps To A Proper Thyroid Diagnosis

1. Do you know your TSH and other thyroid levels or just was informed by your doctor that your labs are “normal”? Ask your doctor what tests does s/he order to check your thyroid.

It is especially important to make sure that an extended thyroid panel was ordered for those who experience hypothyroid symptoms but have TSH in normal range and they have difficulties to get diagnosed.

If you cannot go to the lab you can get a comprehensive thyroid and other testing without visiting the lab. Here is the easiest way to get your thyroid tested now.

thyroid test kit

2. Check what values your doctor and lab are using for normal thyroid levels. Make sure to follow new updated guidelines that recommends TSH normal range between 0.3 and 3.0.

3. Work with your doctor to optimize your thyroid levels for optimal health. Optimal TSH is around 1.0 and free T4 and T3 high normal. This approach is especially useful if you are looking to lose some weight, stop thyroid related hair loss, increase your energy and improve fertility.

4. Measure your body temperature first thing in the morning to evaluate your Basal Metabolic Rate and/or use Dr. Rind’s approach to establish the pattern by using a combination of markers:

  • In a healthy person TSH, T3 and T4 are optimal and body temperature is 98.6.
  • In hypothyroidism the body temperature is below optimal 98.6 but remains stable.
  • In low adrenal function the body temperature is low and unstable but TSH, T3 and T4 are low.
  • In hypothyroidism and low adrenal function the body temperature is low and unstable but TSH is optimal to high and results for T3 and T4 are low.

If your results fit a certain pattern you will get an idea what additional testing you may need to ask your doctor to get a proper diagnosis.

5. Consider additional testing that can include:

6. Go by your symptoms.

Your symptoms are often a better indicator of your health than your blood tests.

Hypothyroidism only Low Adrenal function only Hypothyroidism AND low adrenal function
Low energy levels

Reddish complexion

Thinning of the outer eyebrows


Easy weight gain

Excessive sleep

High blood pressure

Decreased ability to fight infections


Pale face

Full eyebrows

Difficulty gaining weight (if problem is severe)Difficulty losing weight (if problem is moderate)


Un-refreshed sleep

Low blood pressure

Autoimmune disease


Most people have a mixture of symptoms of hypothyroidism and adrenal function

It is important to determine whether problem is with adrenals, thyroid or both because adrenal fatigue must be corrected first.  If adrenal function is low the adrenals cannot handle even normal thyroid activity and thyroid tests can come back indicating hypothyroidism. Unfortunately, many doctors make a very common mistake when they start to treat the thyroid and ignore adrenal problem.

If adrenal function is low prescribing any type of thyroid medication results only in a temporary improvement of symptoms. Increasing the dose of thyroid medication either does not bring any positive results or leads to unsustainable bursts of energy for a short period of time that inevitably end with even lower energy levels.

7. Consider working with an experienced physician who understands the difference between hypothyroidism and low adrenal function and uses a holistic treatment to correct both.

Thyroid Hormone Pathways

P.S. Do you like what you read and want to learn more? Get my FREE Hypothyroidism Diet Guide, FREE Hypothyroidism Seminar: The Right And Wrong Ways To Heal and FREE probiotic, protein and skin cream (worldwide shipping) to improve your thyroid and overall health CLICK HERE

About Marina Gutner, PhD

Marina Gutner, PhD, researcher, medical writer, thyroid blogger, founder and Admin of Outsmart Disease who writes about life-changing treatments for hypothyroidism, Hashimoto's thyroiditis and autoimmune disease and how to balance hormones in women