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Doctor Detective with Spencer Nadolsky
A hidden cause of low thryoid


Jason, an ostensibly fit personal trainer, was tired. He’d been to many doctors, who put him on thyroid replacement without fixing the underlying cause — not enough food, and too much stress.

Eat less and exercise more. It’s generally a great prescription for improving health and improving body composition. However, it doesn’t always work.

Even with an awesome exercise plan and a rock-solid diet, some people suffer from mysterious symptoms and complaints that seem puzzling, given how much effort they put into their fitness and health.

When we meet clients who have problems that exercise and nutrition – not to mention their own doctors – can’t seem to solve, we know there are only a few experts on the planet to turn to. One of them is Spencer Nadolsky.

Dr. Nadolsky is a doctor of osteopathic medicine who’s also studied exercise physiology and nutrition.  An academic All-American wrestler in university, he’s still an avid exerciser and brilliant physician who practices what he preaches to patients – treating preventable diseases first with lifestyle modifications (instead of prescription drugs).

When clients have nowhere else to turn, Dr. Nadolsky turns from a cheerful, sporty doctor into a meticulous, take-no-prisoners forensic physiologist. He pulls out his microscope, analyzes blood, saliva, urine, lifestyle – whatever he has to, in order to solve the medical mystery.

When Dr. Nadolsky volunteered to work on a regular case study feature with us, we jumped at the chance. By following along with these fascinating cases, you’ll see exactly how a talented practitioner thinks. You’ll also learn how to improve your own health.

In today’s case, we meet a young fitness professional who discovers how physical and nutritional stress can affect the thyroid.

The client

Jason, a 25 year old male, sought me out via Facebook to fix his thyroid issues.

Like many patients before him, Jason was fed up with the doctors he had seen in the past, who gave him too little of their time and too much of their prescription pad. Jason was getting the usual run-around that is a product of our health system (and not necessarily the fault of the doctor).

Working online has its limitations, but there are things that I can do, and questions that I can ask, that will help give people clues to solving their medical issues. I couldn’t see Jason in person, but I could certainly listen to him and try to help him work through his situation.

The client’s signs and symptoms

Jason was sluggish and cold. He woke up in the morning freezing and tired, which of course is not a good combination. His libido was up and down with no good rhyme or reason.

Signs / Symptoms My thoughts – potential issues
Fatigue Sleep issues, thyroid, anemia, depression, low testosterone (in males generally), etc
Feeling cold Low thyroid, adrenal insufficiency, malnutrition/anorexia
Low libido Low testosterone, low thyroid, adrenal, malnutrition/anorexia

The thyroid puzzle

About a year or two before our chat, Jason had been feeling worn out. He went to multiple practitioners, including family medicine doctors, integrative medicine doctors, and even endocrinologists, all of whom had varying opinions on what to do.

His endocrinologist said, “Go on testosterone replacement.” His family doctor said, “Get more sleep.”

An integrative practitioner recommended taking Cytomel — the brand name for T3 (liothyronine), the active form of thyroid hormone — based on the labs below, which showed that Jason’s thyroid was running low.

Marker Result Lab Reference Range Thoughts
TSH 5.5 uIU/mL 0.45-4.5 Consistent with subclinical hypothyroidism.
Free T4 0.82 ng/dL 0.82 – 1.77 Low end of normal. Possible hypothyroidism or subclinical hypothyroid.
Free T3 2.1 pg/mL 2.0-4.4 Low end of normal. Possible hypothyroidism or subclinical hypothyroid.
Reverse T3 24.0 ng/dL 9.2-24.1 High end of normal. Possible euthyroid sick syndrome.

These labs sure were interesting for a young and very fit male, whose thyroid should have been revving normally.

This suggested a couple of possibilities.

  • Subclinical hypothyroidism, which is a higher than normal TSH (the hormone from the brain that tells the thyroid gland to work), and normal T3 and T4 (the actual thyroid hormones). In Jason’s case, T3 and T4 were almost out of range on the low end.
  • Euthyroid sick syndrome, which can show variable levels of TSH with a slightly low T3 and high reverse T3.

Having subclinical hypothyroidism would be rare in a male this age, but not completely out of the realm if you remember my patient Steve (the guy with yellow hands). Jason had a similar picture, but without the high reverse T3 (although we never checked it).

Nonetheless, I didn’t think thyroid replacement was the answer.

Ironically, despite his abundant lab work, Jason’s doctors hadn’t checked his thyroid antibodies.

I sent him to get both the anti-TPO (thyroid peroxidase) and anti-thryroglobulin antibodies. If one or both of these were positive, then that could mean Jason’s own body might be attacking his thyroid, as in the case of my previous client Steve’s autoimmune thyroiditis.

Both antibody tests came back negative. This was great news! It gave me hope that I could help Jason get off of his thyroid replacement, but I needed to understand what the underlying issue was, since his thyroid labs were certainly not normal.

I decided to focus on the euthyroid sick syndrome idea, which happens during a non-thyroidal illness such as pneumonia. I see it a lot in hospital patients in the intensive care unit who are very ill. In the hospital, we don’t order thyroid labs unless we truly think a thyroid illness is occurring, because inevitably the thyroid labs will come back abnormal.

This is an important point. Thyroid dysfunction is often a sign of a body under stress.

But Jason was not in the hospital and didn’t seem overtly “sick.” What could be going on?

The starving thyroid?

Jason was a very successful personal trainer and like many others in the field, he was a self-experimenter. As it turns out, during the time he did his panel of lab tests, he was practicing intermittent fasting. He was also going through some very stressful times in his life.

Could these have been the cause of his symptoms and lab results? A little bit of fasting here and there shouldn’t cause this, but if you take it to the extreme, it’s definitely possible.

Our bodies sense starvation in times of extreme caloric deficit. When this perceived starvation happens, one way that the body protects itself and preserves energy is by lowering energy expenditure via the thyroid.

Normally, a healthy thyroid converts T4 hormone to T3 (which, again, is the active form of thyroid hormone). A sick thyroid often converts T4 to reverse T3 instead.

You can see that this might be happening in the labs above.

To prove this was happening, I had him stop the fasting and eat more. I then ordered him labs while he was on the T3 (Cytomel) thyroid replacement. On the T3 replacement, his symptoms were variable, but overall better than what they were before replacement.

The tests and assessments

I ordered the same thyroid panel from above.

The test results

Blood chemistry panel

These are Jason’s lab findings:

Marker Result Lab Reference Range Thoughts
TSH 0.97 uIU/mL 0.45-4.5 Normal and actually optimal
Free T4 0.72 ng/dL 0.82 – 1.77 Low. Will describe below what is going on.
Free T3 3.7 pg/mL 2.0-4.4 High normal range
Reverse T3 11.0 ng/dL 9.2-24.1 Low end of normal

Now, only T4 was abnormal. I would expect to see this, since normally one’s thyroid gland secretes mostly T4 (inactive compared to T3) with only some T3. The T4 is then converted to the active T3 in other parts of the body. Since Jason was taking exogenous T3 (Cytomel), his body isn’t making the T4 anymore, which is why it shows up as low.

Time to test my hypothesis.

The prescription

Part 1: Wean off the Cytomel

I figured this would be the tough part. Cytomel (T3 – liothyronine) was the only thing during Jason’s illness that made him feel better.

At first, I prescribed him a compounded version of it, which could be scaled down gradually. Jason eventually preferred breaking his current tablets and weaning off from there. He started with 6 equal parts of his tablets per day. Every week he would stop taking one of the small bits until he wasn’t taking anything.

Part 2: Fix the diet

I thought Jason’s problems were caused by low calories (and maybe even carbohydrates too). He needed to stop the long fasts and consistently eat at least his calculated caloric needs for the day.

We couldn’t fix the underlying problem without this step.

The outcome

After 2 months, I got more labs done.

Marker Result Lab Reference Range Thoughts
TSH 3.6 uIU/mL 0.45-4.5 Higher than I would want but at least in the normal range.
Free T4 0.92 ng/dL 0.82 – 1.77 On the lower end of normal
Free T3 2.2 pg/mL 2.0-4.4 On the lower end of normal
Reverse T3 20.0 ng/dL 9.2-24.1 On the higher end of normal

While Jason was somewhat discouraged with these lab findings, I knew we were going in the right direction. I continued to encourage him to eat well and maybe even take it easy in the gym for the next month.

I also asked him not to take any more T3, no matter what. I wanted the next set of labs to be accurate.

After 2 more months we got the following labs.

Marker Result Lab Reference Range Thoughts
TSH 2 uIU/mL 0.45-4.5 Normal
Free T4 1.2 ng/dL 0.82 – 1.77 Normal
Free T3 3.0 pg/mL 2.0-4.4 Normal
Reverse T3 15.0 ng/dL 9.2-24.1 Normal

Jason was off T3, and his symptoms were mostly resolved, which made us both very happy.


Jason came to me complaining of fatigue. He’d been to multiple doctors who diagnosed him with various conditions. He was inappropriately started on thyroid replacement without fixing the underlying cause.

By addressing the real problems — metabolic down-regulation because of stress and inadequate food intake — we were able to get Jason off medication and on to a new, healthier path.

What can we learn from Jason’s story?

  1. If you are constantly fatigued, see your doctor.
  2. Hypothyroidism (low thyroid) may be a symptom of something else, and it doesn’t always have to be treated with thyroid replacement.
  3. Find the actual problem. In Jason’s case it wasn’t his thyroid, it was his low calorie intake.
  4. Look at your allostatic load — the sum total of all the mental, physical, and emotional stressors in your life. You may be more stressed out than you realize — and if so, your body will be giving you clues.