Is TSH the only lab that matters—or should I be testing more?
TSH is not the only lab that matters for women with Hashimoto's thyroiditis—and in functional medicine, relying solely on it is one of the biggest oversights in conventional medicine. Many women feel persistently fatigued, brain-foggy, cold, or struggle with weight and mood issues despite "normal" TSH results. As I’ve said before functional medicine looks at the full picture: thyroid hormone production, conversion to T4 to T3, autoimmunity, nutrient status, inflammation, and root causes like gut health, stress, and toxins. It’s all about root cause health- the WHY.
Why TSH Alone Falls Short
TSH (Thyroid Stimulating Hormone) measures how hard your pituitary gland works to stimulate the thyroid. The pituitary sends thyroid stimulating hormone to the thyroid to tell it to make thyroxine or T4.
Conventional medicine uses it as usually the only marker, with "normal" ranges of 0.45–4.5 mIU/L. If TSH is high, doctors prescribe levothyroxine; if normal, they say you're fine. You know if your TSH is within the conventional lab ranges and they say you are fine but you don’t feel fine you are sent away. Women with thyroid problems are often written off as complainers, or they just need to exercise more, or you need an anti-depressant. I’m sure many of you know the drill. I’ve been there too.
In functional medicine, relying solely on TSH is not the best marker to judge your thyroid function by because Hashimoto's thyroiditis is a progressive autoimmune condition where thyroid damage often begins long before TSH becomes abnormal. Even for someone who doesn’t have hashimoto’s and has just hypothyroidism, TSH is not the only or best marker to measure thyroid health. TSH plus Free T4 and Free T3 at a minimum should be measured by each and every doctor you see.
Hashimoto's involves the immune system producing antibodies (primarily TPOAb and TgAb) that attack thyroid tissue, leading to chronic inflammation and gradual destruction of thyroid follicular cells via cell-mediated and antibody-mediated mechanisms.
What exactly does this mean? This is the hard part- I’ve always been told that people don’t want to know the science. I was never like that even before I got my masters in nutrition. I wanted to know what was going on in my body because it helped me make informed decisions about my health, my diet, and my lifestyle. You can skip over this if you want but I feel like if you know what is going in in your body, it might help you understand why you feel the way you do.
Antibody mediated means that a type of white blood cell called a B cell makes TPO antibodies and thyroglobulin antibodies. The antibodies go around in your blood and bind to thyroid proteins. When they bind to those proteins it triggers damage to your thyroid gland in a couple of ways.
It activates a system in within your immune system called complement which is a group of proteins that poke holes in cell membranes, kind of like drilling into thyroid cells. They flag the cells for destruction - for other immune cells called natural killer cells to come in and kill the cells. This process keeps your thyroid from functioning by blocking thyroid peroxidase enzymes. These are the ones that that help T4 and T3 exist. This is why high antibody levels indicate you have hashimoto’s. These things are a sign of the attack and part of the weaponry of the autoimmune process.
Cell Mediated is about the immune attacks carried out by the immune cells themselves rather than the antibodies. It is kind of like hands on destruction. These immune cells, called T cells physically interact with and kill cells targeted for destruction. This is a major player in Hashimoto’s. These immune cells attack thyroid cells and the tissue within the thyroid gland becomes infiltrated with white blood cells out for destruction. This causes inflammation in the thyroid gland, scarring of tissue (this is when an ultrasound comes in handy).
These two processes work together to destroy your thyroid tissue which also can destroy your health, your joy, your energy, your everything. The attack happens gradually and progresses slowly- you can have significant damage before you have symptoms like fatigue, weight gain, etc become so obvious that you know something is wrong.
This process can unfold in stages:
Early stages: Genetic predisposition plus triggers like stress, infections, or toxins lead to elevated antibodies with normal TSH, Free T4, and Free T3—you may already feel symptoms like fatigue or brain fog.
Progressive inflammation: Thyroid becomes leaky or inefficient, but the pituitary gland still compensates by showing normal TSH output.
Later stages: As thyroid tissue is destroyed, hormone production drops, Free T4/T3 decline, and TSH finally rises (often considered "overt" hypothyroidism when TSH >10 mIU/L with low Free T4).
By the time TSH is elevated, significant thyroid damage (up to 90% loss of function in some cases) may have occurred. Functional medicine emphasizes catching and addressing the autoimmune process early, when interventions can potentially slow or halt progression, rather than waiting for TSH to flag overt disease.
Why TSH Doesn't Reveal T4 to T3 Conversion Issues
The thyroid produces mostly T4 (about 93%), an inactive "storage" hormone that must be converted peripherally (mainly in the liver, gut, and kidneys) to active T3 via enzymes called deiodinases. This conversion is crucial because T3 is what binds to receptors and drives metabolism, energy, mood, and virtually every cell function.
In Hashimoto's (and hypothyroidism generally), conversion is often impaired due to:
Inflammation inhibiting deiodinase activity.
Nutrient deficiencies.
Stress or illness shifting conversion toward inactive Reverse T3.
TSH only reflects pituitary signaling based on circulating T4/T3 levels—it doesn't measure how effectively T4 is activated to T3 or if T3 is reaching tissues.
Many women with Hashimoto's have "normal" TSH and Free T4 but low Free T3, leading to persistent hypothyroid symptoms despite treatment. Studies show selenium and zinc are essential cofactors for deiodinases; deficiencies reduce T4-to-T3 conversion, and supplementation can improve it
What High Reverse T3 Means
Reverse T3 (rT3) is an inactive molecule of T3 produced from T4 under stress, inflammation, illness, fasting, or nutrient deficits. It binds to T3 receptors but does nothing—essentially blocking active T3 from working, like putting the wrong key in a lock. This is an adaptive "energy conservation" mode (seen in "non-thyroidal illness syndrome" or "euthyroid sick syndrome").
Elevated rT3 is common in chronic stress, infections, or inflammation—prevalent in Hashimoto's. TSH remains normal because total hormone levels aren't critically low, but cellular thyroid action is impaired, causing hypothyroid-like symptoms. Functional medicine tests rT3 and the Free T3:rT3 ratio (>10–20 ideally) to uncover this hidden issue.
Thyroid Ultrasound: What It Entails and Why It's Recommended
A thyroid ultrasound can visualize the gland's size, texture, blood flow, and any nodules. In Hashimoto's, classic findings include:
Diffuse enlargement (goiter) or atrophy.
Uneven or patchy looking thyroid tissue due to infiltration of white blood cells damaging tissue.
Increased vascularity (inflammation).
Pseudonodules (lumpy appearance from inflammation, not true nodules).
It's recommended at least once (or if symptoms/neck issues) because it confirms autoimmune inflammation even when labs are borderline, rules out nodules/cancer risk, and tracks progression. I’ve never had any practitioner or doctor recommend an ultrasound. I do think it is a good idea.
Why Total T3/T4 Are Less Useful Than Free T3/4
Most thyroid hormones circulate bound to proteins (e.g., TBG). Total T3/T4 measure bound + unbound, while Free T3/T4 measure only the unbound, biologically active fraction available to tissues.
Total T4/T3 can fluctuate misleadingly due to pregnancy, estrogen (birth control), liver issues, or inflammation altering binding proteins—without reflecting true thyroid status. Free levels are more reliable for assessing function, especially in complex cases like Hashimoto's.
Nutrient Deficiencies Critical for Thyroid Function and Immunity
Hashimoto's increases nutrient needs while impairing absorption (due to inflammation/gut issues). Key ones:
Selenium — Supports T4-to-T3 conversion, reduces oxidative stress, and lowers TPO antibodies. Multiple RCTs show 200 mcg/day reduces antibodies by 20–50% in 6–12 months.
Vitamin D — Modulates immunity; low levels correlate with higher antibodies and autoimmunity risk. Supplementation often improves outcomes.
Ferritin (iron storage) — Needed for thyroid peroxidase enzyme (makes hormones). Low ferritin (<70–90 ng/mL) common, causes hair loss/fatigue independent of anemia.
Vitamin B12 — Up to 40% deficient; causes fatigue, neuropathy mimicking hypothyroidism.
Others: Zinc (conversion), iron (synthesis).
Adrenals, Stress, and Blood Sugar in Hashimoto's
Chronic stress is a well-documented trigger for Hashimoto's onset/flares via HPA axis dysregulation, immune shifts toward Th1/Th17 responses, and increased inflammation/oxidative stress. The exact "90%" figure for adrenal dysfunction appears more in clinical cases rather than large peer-reviewed studies—research shows frequent HPA alterations but variable prevalence.
In chronic stress, cortisol patterns (via 4-point saliva/urine) often show:
Early: High overall cortisol.
Prolonged: Flattened curve—low morning (no wake-up surge), high evening (trouble sleeping), or overall low ("adrenal fatigue" pattern).
Blood sugar instability ties to adrenals because cortisol/glucagon raise glucose during stress; unstable sugar (highs/crashes from poor diet) repeatedly activates adrenals, worsening HPA fatigue. This exacerbates both adrenal (anxiety, crashes) and thyroid symptoms (fatigue, conversion blocks via high rT3) by increasing inflammation.
Leaky Gut, Infections, and Molecular Mimicry
Leaky gut (increased intestinal permeability) allows undigested food particles, bacteria, or toxins into bloodstream, triggering systemic immune activation.
In Hashimoto's, this can initiate/maintain autoimmunity via molecular mimicry—where foreign proteins (e.g., gluten's gliadin, bacterial peptides from Yersinia/EBV/H. pylori) structurally resemble thyroid tissue (e.g., thyroglobulin or peroxidase).
The immune attack on the mimic cross-reacts with thyroid, perpetuating antibodies/inflammation.
How General Inflammation Affects Thyroid Health
Chronic low-grade inflammation (from diet, stress, gut issues) promotes autoimmunity by activating immune cells, increasing cytokines that damage thyroid tissue and impair hormone synthesis/conversion.
High-sensitivity C-reactive protein (hs-CRP) and erythrocyte sedimentation rate (ESR) are two common blood tests used to detect and monitor systemic inflammation in the body. They're non-specific—meaning they don't pinpoint the exact source of inflammation—but they're valuable for assessing overall inflammatory status.
hs-CRP: This is a protein produced by the liver in response to inflammatory signals, primarily interleukin-6 (IL-6) and other cytokines released during immune activation. The "high-sensitivity" version detects very low levels of inflammation (below 10 mg/L), making it useful for chronic, low-grade issues rather than acute infections. Levels are categorized roughly as:
Low risk: <1 mg/L
Average: 1–3 mg/L
High: >3 mg/L (with >10 mg/L often indicating acute inflammation)
In functional medicine, hs-CRP is favored because it's more sensitive and responsive to subtle changes.
ESR: This older test measures how quickly red blood cells (erythrocytes) settle at the bottom of a test tube over an hour (reported in mm/hr). Inflammation causes proteins like fibrinogen to clump red cells together, making them settle faster. Normal ranges are roughly 0–20 mm/hr for women (higher with age). It's less specific and can be influenced by anemia, pregnancy, or other factors.
Both rise in response to inflammation from infections, autoimmunity, injury, obesity, or chronic conditions—but hs-CRP tends to rise and fall more quickly, while ESR is slower.
Their Role in Thyroid Dysfunction, Especially Hashimoto's
In Hashimoto's thyroiditis and hypothyroidism, there's often a bidirectional relationship with inflammation: The autoimmune process creates inflammation, which damages the thyroid, and thyroid dysfunction can itself promote systemic inflammation (e.g., through altered lipid metabolism or oxidative stress).
Elevated hs-CRP in Hashimoto's/Hypothyroidism:
Multiple studies show that patients with autoimmune hypothyroidism (including Hashimoto's) have significantly higher hs-CRP levels compared to healthy controls, even in subclinical cases. This reflects low-grade systemic inflammation driven by the autoimmune attack (cytokines like IL-6 and TNF-α stimulating CRP production). Higher hs-CRP is also linked to increased cardiovascular risk in these patients, as inflammation promotes atherosclerosis.
Interestingly, treating with levothyroxine often lowers hs-CRP, suggesting that restoring thyroid function reduces inflammation. However, if hs-CRP remains high despite "normal" TSH, it may point to ongoing root causes like gut issues or other inflammatory triggers.ESR in Hashimoto's/Hypothyroidism:
ESR is typically normal or only mildly elevated in chronic Hashimoto's, unlike in painful subacute thyroiditis (where it's often markedly high, >50–100 mm/hr). Some studies show slight elevations in hypothyroid groups overall, but it's not as reliable or sensitive as hs-CRP for monitoring Hashimoto’s.
How Systemic Inflammation Impacts Thyroid Function
Inflammation doesn't just reflect thyroid problems—it actively worsens them through several mechanisms:
Impaired Hormone Conversion: Inflammatory cytokines (e.g., IL-6, TNF-α) inhibit deiodinase enzymes, reducing conversion of T4 to active T3 and increasing inactive Reverse T3. This contributes to persistent symptoms despite treatment.
Perpetuating Autoimmunity: Chronic inflammation (from any source—gut dysbiosis, food sensitivities, stress) upregulates immune responses, potentially increasing antibody production (TPOAb/TgAb) and thyroid tissue damage.
Direct Thyroid Effects: Severe inflammation can temporarily suppress TSH or cause "non-thyroidal illness syndrome," but in autoimmune cases, it sustains the cycle of destruction.
From a functional medicine perspective, elevated hs-CRP (even mildly, like 1–3 mg/L) or ESR signals broader inflammatory burdens that could be fueling Hashimoto's flares or preventing remission.
Practitioners use these to guide interventions: anti-inflammatory diets (e.g., removing gluten/dairy), gut healing, or addressing infections/toxins. Lowering inflammation often correlates with better thyroid function, reduced antibodies, and improved symptoms.
These markers aren't diagnostic for Hashimoto's alone (antibodies and thyroid hormones are key), but tracking them provides insight into progress beyond TSH. Always interpret in context—work with a practitioner, as levels can fluctuate.
Toxins and Thyroid/Autoimmunity
Environmental toxins act as endocrine disruptors:
Heavy metals (mercury, lead) compete with minerals, increase oxidative stress.
BPA/plastics, pesticides interfere with hormone binding/receptors.
Mold mycotoxins suppress immunity and trigger inflammation.
These can mimic/trigger autoimmunity or directly impair thyroid function.
Gut Hormones for Thyroid Health
If you’re navigating thyroid challenges like Hashimoto’s or Graves’, you might feel tired or moody. As a certified nutrition specialist and licensed nutritionist, I’m here to share how gut hormones support digestion and your thyroid. These hormones regulate digestion, impacting nutrient delivery. Let’s explore how to balance them for a vibrant thyroid, based on nutritional therapy principles.
What Are Gut Hormones?
Gut hormones like secretin and cholecystokinin (CCK) control digestion. Secretin neutralizes stomach acid in the small intestine, while CCK triggers bile release for fat digestion and signals fullness. These hormones ensure your thyroid gets nutrients like selenium and reduce toxin buildup.
Gut Hormones and Thyroid
Balanced gut hormones support efficient digestion, delivering vitamins and minerals to your thyroid. For example, CCK helps absorb vitamin D, crucial for thyroid health. Imbalanced hormones, often from stress or poor diet, can slow digestion, starving your thyroid and worsening fatigue.
Hormones and Inflammation
Imbalanced gut hormones can cause inflammation by slowing digestion, leading to leaky gut or toxin buildup. This stresses your thyroid, especially in autoimmune conditions, worsening symptoms like joint pain.
Common Hormone Imbalances
Factors that disrupt gut hormones include:
Stress: Reduces hormone signaling, slowing digestion.
Poor Diet: Low fat or fiber diets impair CCK.
Overeating: Overwhelms hormone regulation.
These can reduce nutrient absorption and stress your thyroid.
Practical Tips for Thyroid-Friendly Gut Hormones
Here are easy ways to balance gut hormones, fitting your love for home-cooked meals:
Eat Balanced Meals: Include fats (avocado) and fiber (veggies) to stimulate CCK.
Chew Slowly: Take 20-30 seconds per bite to support hormone signaling.
Reduce Stress: Take 5 deep breaths before meals.
Avoid Overeating: Eat smaller, frequent meals.
Stay Hydrated: Drink 8 glasses of water daily.
Try Supplements: Digestive enzymes or bile salts for hormone support at www.outofthewoodsnutrition.com/dispensary (consult your doctor).
Why It Helps
Balanced gut hormones improve digestion, deliver nutrients, and reduce inflammation, easing thyroid symptoms.
Work With Your Doctor
I can guide you with diet and lifestyle. Work with your healthcare provider to monitor thyroid levels and discuss digestion issues.
Take Action
Try a balanced meal with avocado this week. Book a consultation at www.outofthewoodsnutrition.com. Visit www.outofthewoodsnutrition.com/dispensary.
What’s your favorite balanced meal? Comment below!
About the Author: I’m a certified nutrition specialist and licensed nutritionist, helping women with thyroid conditions feel vibrant. Visit www.outofthewoodsnutrition.com for more tips.
Gut Motility for Thyroid Health
If you’re dealing with thyroid issues like Hashimoto’s or Graves’, you might feel bloated or sluggish. As a certified nutrition specialist and licensed nutritionist, I’m here to share how gut motility—the movement of food through your digestive system—supports your thyroid. Good motility ensures nutrient delivery and toxin removal. Let’s explore how to optimize it for a vibrant thyroid, based on nutritional therapy principles.
What Is Gut Motility?
Gut motility is how your digestive system moves food from mouth to colon, ensuring nutrients like iodine reach your thyroid and toxins are removed. Poor motility, like constipation or slow digestion, can trap toxins and limit nutrient absorption, worsening thyroid symptoms like fatigue.
Motility and Thyroid Function
Good motility ensures regular bowel movements (1-3 daily), which remove toxins and balance hormones like estrogen that affect thyroid function. Slow motility can increase inflammation, stressing your thyroid, especially in autoimmune conditions.
Causes of Poor Motility
Factors that slow gut motility include:
Low Fiber: Reduces bowel movement frequency.
Stress: Slows digestion via the vagus nerve.
Dehydration: Hardens stool, slowing elimination.
These can worsen thyroid symptoms like brain fog.
Practical Tips for Thyroid-Friendly Gut Motility
Here are easy ways to boost motility and support your thyroid, fitting your love for home-cooked meals:
Eat High-Fiber Foods: Try beans or leafy greens to promote regular bowel movements.
Stay Hydrated: Drink 8-10 glasses of water daily to soften stool.
Reduce Stress: Take 5 deep breaths before meals to activate digestion.
Move Your Body: A 10-minute walk after meals aids motility.
Limit Processed Foods: Swap chips for fiber-rich snacks.
Try Supplements: Psyllium husk or magnesium for motility at www.outofthewoodsnutrition.com/dispensary (consult your doctor).
Why It Helps
Good gut motility delivers nutrients, removes toxins, and reduces inflammation, easing thyroid symptoms.
Work With Your Doctor
I don’t diagnose, but I can guide you with diet and lifestyle. Work with your healthcare provider to monitor thyroid levels and discuss motility issues.
Take Action
Try adding beans to a meal this week. Book a consultation at www.outofthewoodsnutrition.com. Visit www.outofthewoodsnutrition.com/dispensary. Reply for a custom tip!
What’s your favorite high-fiber food? Comment below!
About the Author: I’m a certified nutrition specialist and licensed nutritionist, helping women with thyroid conditions feel vibrant. Visit www.outofthewoodsnutrition.com for more tips.
Gut Microbiome Diversity for Thyroid Health
If you’re battling thyroid symptoms like fatigue or mood swings from Hashimoto’s or Graves’, your gut microbiome diversity could be a game-changer. As a certified nutrition specialist and licensed nutritionist, I’m here to explain how a diverse gut microbiome supports your thyroid. Let’s explore how to boost diversity for a vibrant thyroid, based on nutritional therapy principles.
What Is Gut Microbiome Diversity?
Your gut microbiome is a community of trillions of bacteria, and diversity means having many different types. A diverse microbiome supports your thyroid by:
Producing anti-inflammatory compounds like butyrate.
Supporting T4-to-T3 conversion for energy.
Balancing hormones like estrogen that affect thyroid function.
Low diversity, often from poor diet, can increase inflammation, worsening thyroid symptoms.
Microbiome Diversity and Thyroid
A diverse microbiome helps convert T4 to T3 and reduces inflammation, key for autoimmune thyroid conditions. For example, low diversity might reduce butyrate, worsening joint pain or brain fog. A 2021 study linked diverse microbiomes to better thyroid function.
Causes of Low Diversity
Factors that reduce microbiome diversity include:
Limited Diet: Eating the same foods daily.
Processed Foods: Starve beneficial bacteria.
Stress: Disrupts gut balance, impacting thyroid health.
These can limit nutrient absorption and stress your thyroid.
Practical Tips for Thyroid-Friendly Microbiome Diversity
Here are easy ways to boost diversity and support your thyroid, fitting your love for home-cooked meals:
Eat a Variety of Plants: Try 20-30 different veggies, fruits, and grains weekly.
Include Fermented Foods: Add yogurt or kimchi for beneficial bacteria.
Reduce Stress: Take 5 deep breaths before meals to support digestion.
Limit Sugar: Swap sweets for fruits to feed good bacteria.
Stay Hydrated: Drink 8 glasses of water daily.
Try Supplements: Probiotics or prebiotics for diversity at www.outofthewoodsnutrition.com/dispensary (consult your doctor).
Why It Helps
A diverse microbiome reduces inflammation, supports thyroid hormones, and eases symptoms like fatigue.
Work With Your Doctor
I don’t diagnose, but I can guide you with diet and lifestyle. Work with your healthcare provider to monitor thyroid levels and discuss gut health.
Take Action
Try a new veggie this week. Book a consultation at www.outofthewoodsnutrition.com. Visit www.outofthewoodsnutrition.com/dispensary.
What’s a new plant food you’ll try? Comment below!
About the Author: I’m a certified nutrition specialist and licensed nutritionist, helping women with thyroid conditions feel vibrant. Visit www.outofthewoodsnutrition.com for more tips.
Nutrient Timing for Thyroid Health
If you’re managing thyroid issues like Hashimoto’s or Graves’, you might feel tired or bloated. As a certified nutrition specialist and licensed nutritionist, I’m here to share how nutrient timing—when and how you eat—can optimize digestion and support your thyroid. Let’s explore simple ways to time your meals for a vibrant thyroid, based on nutritional therapy principles.
Why Nutrient Timing Matters
Eating at the right times supports digestion, ensuring your thyroid gets nutrients like iodine and selenium. Poor timing, like eating too quickly or late at night, can stress your gut, reducing nutrient absorption and worsening thyroid symptoms like fatigue or brain fog.
Timing and Digestion
Your digestive system works best when:
Meals Are Spaced: 3-4 hours apart allows digestion to complete.
You Eat Calmly: Reduces stress, boosting stomach acid and enzyme activity.
You Avoid Late Meals: Late eating can disrupt digestion, impacting nutrient delivery.
Proper timing ensures nutrients reach your thyroid efficiently.
Timing and Inflammation
Irregular meal timing can cause inflammation by stressing your gut, worsening autoimmune thyroid symptoms. For example, eating under stress might reduce zinc absorption, increasing joint pain.
Common Timing Issues
Skipping Meals: Disrupts digestion, starving your thyroid.
Eating on the Go: Reduces saliva and acid production.
Late-Night Eating: Slows digestion, trapping toxins.
These can worsen thyroid symptoms like mood swings.
Practical Tips for Thyroid-Friendly Nutrient Timing
Here are easy ways to time meals for thyroid health, fitting your love for home-cooked meals:
Space Meals: Eat every 3-4 hours to support digestion.
Eat Mindfully: Take 5 deep breaths before meals to relax.
Avoid Late Meals: Finish eating 2-3 hours before bed.
Include Nutrient-Dense Foods: Try salmon or nuts for thyroid support.
Stay Hydrated: Drink water between meals.
Try Supplements: Digestive enzymes for better nutrient absorption at www.outofthewoodsnutrition.com/dispensary (consult your doctor).
Why It Helps
Proper nutrient timing improves digestion, delivers nutrients to your thyroid, and reduces inflammation, easing symptoms.
Work With Your Doctor
I don’t diagnose, but I can guide you with diet and lifestyle. Work with your healthcare provider to monitor thyroid levels and discuss meal timing.
Take Action
Try spacing meals 3-4 hours apart this week. Book a consultation at www.outofthewoodsnutrition.com. Visit www.outofthewoodsnutrition.com/dispensary. Reply for a custom tip!
What’s your meal timing routine? Comment below!
About the Author: I’m a certified nutrition specialist and licensed nutritionist, helping women with thyroid conditions feel vibrant. Visit www.outofthewoodsnutrition.com for more tips.