I’ve heard the story hundreds of times in one form or another. There’s the fatigue, weight gain, depression, hair loss, constipation, dry skin, irregular periods, maybe fertility problems, a miscarriage – or both – or intense fatigue and difficulty producing enough breast milk after you’ve had your baby. You convince your doctor to test your thyroid because you’ve read that thyroid labs could be causing these symptoms. She does and tells you, upon reviewing the results, that your thyroid isn’t the problem. It’s probably just stress, the fact that perhaps you had a new baby and are naturally exhausted and overwhelmed, that miscarriages are common and you can try again, or that perhaps you are really just emotionally depressed and should take an antidepressant. Then time passes. Maybe you take the antidepressant, maybe you don’t. But the symptoms don’t really go away. You’ve gained more weight, you’re more tired, and this whole situation is so depressing that you start to wonder if you really do have a mental health problem.

In desperation, you go to a different doctor. She orders a more complete range of tests because now that you’ve done your research using “Dr. Google,” (or Dr. Aviva!) you know what to ask for. Perhaps you had to insist – but either way she ran the tests. And voila, after all of these months of suffering and worrying, guess what, you really do have a thyroid problem!

The Thy-Gap: Why Thyroid Tests Don’t Always Reveal the Whole Picture

Most of us, whether as doctors or patients, have been led to believe that medical guidelines and practices are pretty much set in stone, and are based on hard reliable facts. The former is definitely not true, in fact, in just the past 5 years or so, it’s been found that many long-followed medical guidelines aren’t correct – guidelines have changed at least on the following: when and how often women need pap smears, how often women need mammograms, the safety of and when to use statin drugs, the safety of and when to use aspirin to prevent heart attack, the safety and use of ibuprofen and other NSAIDS, whether men need the PSA test, how long women should be in labor before they are induced, the level of blood pressure at which high blood pressure should be diagnosed in otherwise healthy adults over 50, the level at which diabetes should be diagnosed …. and I could go on.

It has been found that sometimes, doing tests or interpreting them inappropriately can even lead to harm. For example, hundreds of thousands of young women had pap smears that led to LEEP procedures and cone biopsies that caused scar tissue to the cervix that ultimately led to difficulty dilating in labor when they eventually had children. We now know that women under 21 years old should never have a pap smear because the results aren’t useful in that age for a variety of reasons I won’t belabor here.

Perhaps an even more closely related example that parallels thyroid testing is lead testing. Until just a couple of years ago, kids had to have a lead level > 10 to be diagnosed with lead toxicity. Integrative and functional doctors have been saying that number is too high for years – decades even. It was only recently determined that in fact, at lead levels of over 5 kids can experience damage due to toxicity, thus the standard range of normal was lowered.

On top of this, medical guidelines, while based on hard data, are only as good as the data they are based on, and on what’s known at the time the guidelines are made. So for example, the TSH lab values for normal are based on TSH averages for most generally healthy Americans. But many Americans are under- diagnosed for thyroid disease. When we take an expanded view of thyroid health, and only include the TSH average of people with absolutely no hypothyroid symptoms, the number changes. I’ll tell you more about this in a minute.

The truth is that the correct set of thyroid tests, along with proper interpretation of the results, usually does tell the whole truth about your thyroid health. The problem is that:

  1. Most doctors don’t order a complete set of thyroid labs initially, and only do so if the initial result is abnormal, and
  2. Most doctors are taught a limited set of parameters for interpreting lab tests that don’t always catch everyone with a thyroid problem, particularly Hashimoto’s thyroiditis, or autoimmune hypothyroidism.

As with the lead testing parameters, until recently when the range for normal was made narrower, thus catching more kids with elevated blood levels lead at risk of toxicity, the TSH range for normal starts too high – in fact, until not long ago, it was even higher than it is now – leaving many women with hypothyroidism undiagnosed, sick, and untreated. 

As many as 10% of all Americans have a thyroid problem, mostly women, and many have a slow functioning thyroid and just haven’t been properly diagnosed. In a world where medical over-testing is rampant, I have to say, I find myself confounded by the fact that so many physicians are resistant to ordering anything but a TSH – or thyroid simulating test – as the first form of evaluation, when from a scientific and medical standpoint, that test can be normal and there can still be a low functioning thyroid. It’s outdated medical dogma to order solely this test, and I almost always order a full panel when I am presented with a patient with common symptoms of hypothyroidism.

As for the limited interpretation of thyroid labs, this is because there are differences of opinion between various professional medical groups as to how high the TSH should be before we diagnose someone with hypothyroidism. This leads to what I talked about on Dr. Oz – the “thy-gap” – in which you might have thyroid symptoms, and in fact hypothyroidism, but according to your doctor, your labs are normal.

In fact, not many years ago, that number was a lot higher than it is now; so many more women were told they had normal thyroid function when they did not. Many of us contend that this number is still too high, and in fact, when you test the general public who have no symptoms of hypothyroidism, the average TSH is much lower than the number used to decide whether you have a thyroid problem. If that number were brought down closer to the healthy thyroid general public, more women who have thyroid symptoms would get a diagnosis. Now I’m not for over-testing or over-diagnosis of any sort, but I’m also not for women suffering with symptoms that they are told are probably just in their heads – when they are not!

Read on to see if you should have thyroid testing, what to get tested for, and what results indicate that you might have a thyroid problem.

When to Get Thyroid Testing

Here are some of the most common symptoms of a slow functioning thyroid that suggest thyroid testing might be a good idea:

  • Cold intolerance
  • Constipation
  • Depression
  • Fatigue
  • Goiter (swelling in the front of the neck)
  • Hoarseness
  • Impaired memory
  • Infertility
  • Menstrual disturbance
  • Miscarriage, especially with any of these other symptoms
  • Muscle cramps or weakness
  • Nerve pain, carpal tunnel syndrome
  • Postpartum depression
  • Slow heart rate
  • Slowed mental processing
  • Slowed physical movements
  • Swelling or puffiness around the eyes
  • Weight gain

Also, if any of these lab results is part of your medical story, thyroid testing should be done:

  • Anemia with large red blood cells (macrocytic anemia)
  • High cholesterol
  • High serum muscle enzyme concentrations
  • History of autoimmune disease
  • Low sodium

The Thyroid Labs I Recommend

There are 6 key tests that can unlock the mystery of your thyroid function and are what your doctor should be looking at. Thyroid testing should be simple to obtain from your primary doctor or local lab. However, the nuances may take some skill to interpret, depending on the results, and your doctor might be resistant to ordering more than the TSH test. That’s where an open-minded endocrinologist or a skilled Functional Medicine doctor can be of help!

In my practice, if my patient’s symptoms are highly suggestive of hypothyroidism, I will run the entire thyroid panel described below right from the start. If there are other diagnoses that are equally likely to explain the symptoms, I will run just the TSH, FT3, and FT4 while testing for other causes, for example, anemia, other autoimmune conditions; if the thyroid labs come back borderline or positive for thyroid or thyroid hormone problems, I will then add in the remainder of the tests. I will also sometimes recheck test results for TSH, FT3, and FT4, if normal in a newly symptomatic patient, in 6-12 weeks, because I’ve occasionally seen initial testing be normal then a short time later, voila – the tests come back confirming the problem.

Thyroid Stimulating Hormone (TSH)

Thyroid Stimulating Hormone (TSH) is produced in a part of your brain called the pituitary gland. The job of TSH is to tell the thyroid gland that it’s time to get busy producing more thyroid hormone. When the healthy thyroid gets this chemical message, it produces two hormones: triiodothyronine (T3) and thyroxine (T4), The normal range for TSH is somewhat controversial. Most labs consider the upper range to be between 4 and 5 mU/L. However, many experts – even in conventional endocrinology – believe that the upper end of normal is actually more like 2.5-3 mU/L. This is based on the fact that when Americans without any hypothyroid symptoms have this test done, that is the most usual upper range.

Many integrative and functional medicine doctors find that their patients feel their best at an upper limit of 1.5-2 mU/L.

My patient was one of these people. At a TSH of 4 she was really at the upper limit of normal, over the preferred upper limit according to some docs, and well over the 1-2 mU/L upper range! This controversy and discrepancy of opinion over the normal upper range for TSH is one of the most common reasons that women get under-diagnosed for hypothyroidism and suffer with unnecessary symptoms that can seriously interfere with health and quality of life.

In most cases hypothyroidism occurs because the thyroid gland is sluggish – that is, it is having trouble producing T3 and T4. This can be due to a variety of reasons ranging from nutritional deficiencies to autoimmunity. So TSH gets pumped out in a higher amount to try harder to stimulate the thyroid gland into action. Think of it like this: You are TSH. Your best friend’s house is the thyroid gland. When you go to visit your friend you knock on her front door. If she doesn’t answer, what do you do? You knock louder to get a response. In just the same way, the TSH amps up to knock louder, hoping to get an answer. That’s why an under-functioning thyroid shows up as high TSH on lab tests. However, TSH can be normal in the presence of hypothyroidism in some cases, and you can still be having the symptoms of low thyroid when TSH is normal because of poor conversion of T4 to T3 (see below) or because of thyroid hormone resistance at the level of your cells.

When stress is suppressing the pituitary gland enough to interfere with producing TSH, you might see low or normal TSH levels in the presence of low thyroid hormone production (T3 or T4), and hypothyroid symptoms.

Thyroid Hormones (T3 and T4)

Triiodothyronine (T3) and thyroxine (T4) are the hormones produced by your thyroid gland. T4 is produced in a much larger amount and is then converted to T3, the active form of the hormone, as needed to up-regulate metabolic functions. T3 and T4 are sent out into your bloodstream where they are responsible for the thyroid’s actual work of controlling your metabolism. Free T3 (FT3) and Free T4 (FT4) are called this because they are not bound to proteins in your blood, making them free to perform their work in your cells – keeping your metabolism appropriately revved up for your optimal health.

Measuring FT3 and FT4 is important because they are the indicators of thyroxine and triiodothyronine activities in the body. A high TSH and low FT4 and FT3 indicate hypothyroidism. A normal TSH, normal FT4, and low FT3 can indicate T4 to T3 conversion problems, and a normal or high TSH, normal FT4 and high FT3 can indicate cellular resistance to FT3 which can still lead to hypothyroid symptoms because the active hormone can’t get to the cell to do its job.

Thyroid Antibodies

Thyroid antibody testing is ordered to diagnose autoimmune thyroid disease and distinguish it from other forms of thyroid dysfunction.

The two thyroid antibody tests that I order are Thyroid peroxidase antibody (TPOAb) and Thyroglobulin antibody (TgAb). Some people do have an autoimmune thyroid condition but don’t initially test positive. If positive, antibody testing can be repeated every six months to trend improvement while you are working with an integrative physician to address possible underlying causes.

Reverse T3 (rT3)

Reverse T3 is the third most abundant form of thyroid hormone. When your body wants to conserve – rather than “burn” – energy, it will divert the active T3 into an inactive “reserve” form. This might happen when you are sick, under stress, or undernourished. If TSH and FT4 look ok, but FT3 is low this can be because it is being diverted into rT3 – which will be elevated. It is worth checking rT3 if there are obvious symptoms suggesting hypothyroidism, but the typical tests aren’t demonstrating low TSH or low FT4. There is some controversy among conventional doctors about the utility of this test – I personally find it very useful.

Interpreting Thyroid Labs Properly

As I stated earlier, most doctors are taught a limited interpretation of thyroid labs, in which hypothyroidism is diagnosed only when the TSH is above about 4.5 to 5.0 mU/L. However, a paper published by the National Academy of Clinical Biochemistry argues that the upper limit of normal should be reduced to 2.5 mU/L because 95% of rigorously screened volunteers with no symptoms and healthy thyroid function have serum values between 0.4 and 2.5 mU/L and a large study from Germany found a normal reference range of 0.3 to 3.63 mU/L. Controversy also exists as to whether those with a TSH of between 5 and 10 mU/L need to be treated, even if they have symptoms.

Over 2.5 in the first trimester, and 3.0 in the second and third trimesters are considered the upper limit for TSH in pregnancy, and indicate the need for treatment.

In my practice, if the level is over 2.0 mU/L and there are symptoms, I treat for hypothyroidism, even if someone is not pregnant. If there are no symptoms at all, and the level is under 3.5, I usually don’t treat, but I then trend thyroid levels for the next 12 months, testing again in 3 months, then again 6-9 months later, and I test for thyroid antibodies, because often thyroid antibodies are a harbinger of thyroid problems to come.

If TSH is normal, but FT3 is low, then I might supplement with FT3 only, and I explore factors that might lead to poor conversion of FT4 to FT3. I also check reverse T3 (rT3) because stress, infection, inflammation, elevated cortisol, and poor nutrition, among a number of factors, can cause the body to divert FT4 to rT3 in an effort to “lower the body’s thermostat” and conserve energy by slowing down the thyroid. This is a biological protection mechanism, similar to setting the thermostat at lower temperature during an energy crisis. 

TSH, FT3, and FT4 can also be normal when there is thyroid hormone resistance – the thyroid is working just fine, but thyroid receptors on cells aren’t letting thyroid hormone in, so it can’t do its jobs. This can be a result of high cortisol due to stress, infection, or inflammation, and may also be associated with high homocysteine, which can occur when there is an MTHFR genetic change, which can be tested for by your doctor or a local lab. If present, methylfolate, 800-1000 mcg/day for adults, is usually recommended to accommodate for the genetic change.

The most important takeaway here is that in order to get to the bottom of your symptoms, and get appropriate treatment, you have to start with a proper diagnosis. I hope you are able to use this article to discuss your symptoms, thyroid labs, and thyroid results with your care provider to get the answers you need, and the treatment that will help you to feel better!

38 Comments

  1. Great informative article! Now can you please post on adrenal fatigue and testing, as well as how adrenal function ties into thyroid functioning. Thanks

  2. This problem is real. Lost over two years mid career and had to start over because of constant misdiagnosis. The really amazing thing about this is that on my family history I wrote EVERY TIME that my mother suffered from Hashimotos. Only knew this because she joked about it when first diagnosed, but had no idea what it meant. But medical professionals should have and they should have seen it was a red flag.

    Instead people though Epstein-Barr, Chronic Fatigue Syndrome and these days would probably be diagnosed as issue with adrenaline overload. But even those were better than the continuing barrage of doctors who didn’t believe and wanted to put my on antidepressants. Luckily am both stubborn and bad at taking meds (if there’s a side effect I’ll find it — the rarer the better) so you can guess my reaction.

    In me the effect was for me was that had enough energy to live my life or recover from an illness but not both. So any time I got sick, it went on and on and on until finally sapped of all energy could do nothing but rest for weeks. Since I was self-employed this was even worse than it sounds. If this sound familiar get checked.

    • This depends on what patients have tried in the past, and whether they prefer a natural or synthetic supplement — but yes, I do use levothyroxine in my practice.

    • Hi Rebecca,
      Depends on the nature of the consult — asking questions vs me actually prescribing. Here are the 2 options for consulting with me

      1. Become a patient in my medical practice, Thrive Health, which you can find out more about here: https://avivaromm.com/health-consultations

      or

      2. Through an Integrative TeleWellness Consultation if you’d like to discuss your health and wellness concerns with an expert in Integrative and Functional Medicine for women and children, and you don’t have this option in your community, or if are to unable see me in person as a patient. To learn more go here: https://avivaromm.com/integrative-telewellness-consultations

      With warmest wishes,
      Aviva

  3. Hi Aviva! Another great article!! Thank you! I have a TSH of 5.5 and have had all of these other thyroid tests that you wrote about come back normal. My only real symptoms potentially associated with hypothyroid are elevated cholesterol, and maybe brain fog. Do you ever recommend treating if the Patient doesn’t have fatigue, constipation, etc?

      • My Dr. says my thyroid isn’t at a level that would indicate a problem. Yet in the past three years I’ve gained 50lbs, I’m exhausted, I have serious brain fog issues and yes this makes me depressed. I won’t take anti-depressants as they keep me in a stupor. My cholesterol is very high even tho I’ve totally changed the way I eat and have increased the amount of excersize I get. I’ve gone from being a very active construction Boilermaker to a 59yr old women on a disability in two years time. I could weep. What specifically should I ask my doctor to do as testing for thyroid. He only wants to prescribe anti-depressants and thats just not an option I’ll take.

        • Hi Shelby,

          If you go to Aviva’s website and download her Thyroid Insights e-book you will find a detailed list of the tests that she likes to work with. I am so sorry to hear of your struggles working with an integrative or functional medicine doctor to get to the root of what is going on for you may be a good next step.

          Warm wishes,
          Megan- Aviva Romm’s Executive Assistant and Online Nutrition Expert

  4. Thanks Aviva, I would love to do a specific course related to health professionals treating thyroid disease and Hashimotos…what do you think? I have a client now with high high antithyroid antibodies. Resources here are limited to do more panels of tests for checking heavy metals, parasites and food allergies. Also do you prescribe one set of vitamin supplements all in one or separately to get the optimal amounts?
    Thanks

  5. Aviva, this was such a useful article! Wondering if it would be possible for you to make up a thyroid chart we can take to our doctors to make talking through these options a little more easy. (I tend to have a foggy memory and although I know and understand the importance of what you wrote in this article it will be challenging for me to articulate it with my doctor.

  6. thank you so much for writing this. I was diagnosed with hypothyroidism last May and started on levotyroxine 25. they had to remove half of my thyroid because I had a large tumor on one side. I have had to keep calling my doctor to ask about getting blood work to check my levels, one time I go she says they are fine and the next they aren’t. I am at 75 now and I still don’t feel any different. I continue to gain weight like crazy, I eat pretty well, exercise, I am exhausted all the time, my hair falls out I’m like a shedding dog all the time and my skin is so dry all the time. When I had my last blood work done it came back 4.3 and she said I was fine. Now after reading what you wrote it has got me thinking. thank you so much for your article!!

    • Been diagnosed with hypothyroidism for over 10 years- on thyroid meds, but kept gaining 5 lbs per year, despite almost starvation level diet of good food and exercise. Began the “Fast Metabolism” diet ( there is a book and website) and for the first time, lost weight ( 25 lbs) and kept it off and feel much better for over a year. Recommend it to anyone with hypothyroidism- try it for at least the month. I do not have any connection or funding, etc. from the creator of the diet- but I want to share what finally worked with other with hypothyroidism, as I understand the struggles..

  7. it is a good article but would be helpful to have a list of all to test for, so when I go to a private lab because my insurance only pays for testing for T3 and T4, I can just hand them a piece of paper with the laundry list of things to test. Thanks in advance!

    • Thank you for this feedback! I’ll be happy to do a blog on this topic, and my forthcoming adrenal-thyroid book will have lab info — but that’s not until Jan 2017 — so I’ll do a blog sooner! LOL!

  8. Wonderful article. I too went years not knowing I ha PCOS or Hypothyroidism because I wa on the pill. Met a fabulous RE to assist us in our infertility journey who diagnosed me. Quite honestly it’s been me ever since because my RE retired the month we got pregnant and my family doctor did not keep up the same testing with my first or second pregnancy. I am doing much better how living a more natural life and am going to be taking a more natural approach with my thyroid too!

  9. I was diagnosed with hashimotos after ending up in the hospital when I was 16. It definitely runs in my family since my dad, grandmother, sister, and aunts have it also. I have been on synthroid since then and sometimes it gets changed but generally it stays around the same dose. I felt dead without the synthroid, I might as well have been dead because that is where I was going fast. People do not normally think kids can get this…not sure why and if they do they will not treat them because they say the medicine eats your bones basically. Well it has not eaten my bones and I am Program Chair of Health Care at a huge University now. My question is this, my daughters 14 and 16 both have 85% percent of the symptoms you mention and they will only do a TSH on them which comes out around 3 on both of them. They say that means they are fine. We both know a TSH is useless by itself. One kid is actually quite sick now and I believe it is from this…or at least a large part of it is from this. The other has gained 25 pounds in a year, bleeds heavily, lost a great deal of hair, is always tired, eats normally and is quite depressed. I am unsure what to do to help them since the medical community will not touch this issue in kids. The local endocrinologist will not see them even for me. Are they right? Can this not occur in kids..it did in me! I was sick for over a year …and I mean passing out on the floor in school and everything…before I finally crashed and they did a simple blood test. People do not realize you can have a heart attack from it. Any information or direction would be greatly appreciated since I am sure it impacts more than just my kids. Thank you and I think you are wonderful!

  10. Just like Amy I’m tired of fighting. I have a goiter with nodules that had a biopsy. Can only get docs here to perform 2 tests. Have 2 daughters with Hashimotos. A sister who had gee goiter removed last year. It tested for cancer. My grandmother had gear goiter removed. Why won’t docs do more of thes tests. Obviously my thyroid is not workin right. Where can I go next?

    • Hi Merrilyn,

      Thank you for writing and sharing your story and I am so sorry to hear that you are not being heard. We recommend looking on the website of the Institute for Functional Medicine (https://www.functionalmedicine.org/) for a practitioner in your community. Wishing you ease and health and I hope that you are able to find a Dr. in your community who will listen.

      Warm wishes,
      Megan- Aviva Romm’s Executive Assistant and Online Nutrition Expert

  11. You go girl. My sister had t3,t4 and tsh tests for years. She would clean out the refrigerator every day. Her physician told her to see a nutritionist. After suffering for a very long time, like 10 years, she got a scud missile type headache and a cat scan was done. The pituitary tumor was 3.5 cm. big by then. Her prolactin was off the charts. Her only symptom was the hunger for a very long time. The t3,t4 and tsh were normal for years. By then the tumor was too big to radiate.

  12. I have been struggling with fatigue for over 10 years and everything you say rings true to my story. I was tested for thyroid years ago and it was low functioning but the Drs said it wasn’t low enough to warrant further investigation. I finally got an adrenal test and came back stage 3, which I have been addressing with daily herbs (DHEA, Pergenelone, Licorice root), however I never get fully better, was told to stop all caffeine, but have not cause I love my morning coffee and run/exercise, I think it’s the thyroid in addition, I should still be able to have caffeine and exercise in the morning without feeling like crap the entire day right? I just bought your book and I’m ready to re-evaluate all this based on your suggestions, I hope I can find a decent Dr in SF – any additional advice for a testing and wellness roadmap would be great, thank you!!

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