Thyroid Terminology & Definitions

Introduction: Why Understanding Thyroid Terms Matters

Misunderstanding thyroid terms can delay diagnosis, lead to under-treatment, and leave root causes ignored. At Patients Medical in New York City, we empower you with clarity—explaining essential thyroid language so you can actively participate in your health journey.

When you understand terms like Reverse T3, TSH antibodies, and Free T3 levels, you’re better equipped to ask the right questions—and to find personalized, integrative solutions.

Key Thyroid Terms You Should Know

TSH (Thyroid-Stimulating Hormone)

Produced by the pituitary gland, TSH regulates thyroid hormone production. It’s the most common blood test for thyroid function—but it’s only the starting point in a full evaluation.

Free T4 & Free T3
  • Free T4 (Thyroxine): The inactive storage form of thyroid hormone.
  • Free T3 (Triiodothyronine): The active hormone that enters your cells and controls metabolism.
Reverse T3 (rT3)

An inactive form of T3. High rT3 can block the action of Free T3, resulting in symptoms despite normal TSH.

Thyroid Antibodies (TPO-Ab, TG-Ab, TRAb, TSI)

These include:

  • TPO-Ab and TG-Ab: Markers of autoimmune thyroiditis (e.g., Hashimoto’s).
  • TRAb/TSI: Indicators of Graves’ disease.

Nodules & Goiter
  • Nodule: A lump in the thyroid; mostly benign but should be evaluated.
  • Goiter: A diffuse, enlarged thyroid gland, often linked to autoimmunity or nutrient deficiency.
Subclinical Hypothyroidism

A lab pattern where TSH is mildly elevated, but Free T4 is normal—symptoms may still be present.

Euthyroid

Refers to a normally functioning thyroid gland.

Bioidentical Thyroid Hormones

Natural hormone replacements (e.g., Armour, compounded T3/T4) that closely mimic your body’s own thyroid hormones.

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Why These Definitions Matter

Understanding these terms allows you to recognize how your body is truly functioning—or malfunctioning. It provides insight beyond basic labs, revealing whether:

How We Apply These Concepts at Patients Medical

  1. Personalized Lab Evaluation:
    We order a full thyroid panel—including all of the terms above—plus nutrient status and markers of inflammation.
  2. Interpretation With Context:
    We assess labs alongside your symptoms, genetics, and lifestyle.
  3. Customized Treatment Plans:
    • Food and supplement protocols to support thyroid function
    • Bioidentical thyroid hormone if needed
    • Gut, adrenal, and detox support to improve hormone conversion
  4. Ongoing Monitoring & Support:
    We work with you to understand your results over time and adjust care to promote optimal well-being.

Common Misconceptions (Clarified)

Term

Misunderstanding

Why It Matters

Normal TSH

“I’m fine”

TSH may not reflect low T3 or high rT3

Low TSH = Hyperthyroid

Always overactive gland

Could be suppressed during illness

No antibodies, no autoimmunity

There’s no disease

Antibodies can wax and wane over time

Reverse T3 isn’t important

It’s always ignored

High rT3 blocks metabolic hormone

Testimonials

Frequently Asked Questions

Yes! Many patients reduce antibodies and symptoms through immune modulation and gut healing.

For patients with conversion issues, NDT often provides better symptom relief. We personalize based on labs.

Most notice improvements in 4-8 weeks; full stabilization takes 3-6 months.

We provide superbills for out-of-network reimbursement. Some tests may be covered.

We coordinate with endocrinologists for ultrasounds and offer selenium/iodine protocols when appropriate.

Begin Your Journey with Patients Medical

Patients Medical specializes in gently helping the patient identify the root cause of their medical issues and then assist them to recover from their problems to help them move forward to good health.

Request your consultation today!

To schedule an in person on Tele-medicine appointment, please call our office at (212) 794-8800 or email us at info@PatientsMedical.com We look forward to hearing from you

Our medical center in New York City.

Patients Medical PC
1148 Fifth Avenue, Suite 1B New York, NY 10128

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