UNDERSTANDING YOUR THYROID LABS: A SIMPLE GUIDE (again)

Not let's start here -Your thyroid is a small butterfly-shaped gland in your neck — but it has a huge impact on your energy , weight , mood , hormones , and overall health.

If you’ve ever looked at your thyroid blood test results and felt confused, you’re not alone. Let’s break down the most common thyroid labs and what they mean:

1. TSH (Thyroid-Stimulating Hormone) 
What it does: TSH is made by your brain and tells your thyroid to produce hormones.
Normal range: Around 0.4–4.0 MIU/L (some feel best between 0.5–2.5)
 High TSH = Underactive thyroid (hypothyroidism)
 Low TSH = Overactive thyroid (hyperthyroidism)

2. Free T4 (Thyroxine) 
What it does: The main hormone your thyroid makes. “Free” means your body can use it.
 Low Free T4 + High TSH = Hypothyroidism
 High Free T4 + Low TSH = Hyperthyroidism

3. Free T3 (Triiodothyronine) 
What it does: The active form of thyroid hormone that powers your metabolism, energy, and mood.
 Low Free T3 = Poor conversion from T4 → T3 (can happen with stress or inflammation)

4. Reverse T3 (rT3) 
What it does: A “brake” hormone that blocks the effects of active T3.
 High Reverse T3 = Your body may be in survival mode (stress, trauma, illness)

5. Anti-TPO (Thyroid Peroxidase Antibodies) 
What it does: A key marker for thyroid autoimmunity.
 High Anti-TPO = Common in Hashimoto’s or Graves’ disease

6. Anti-TG (Thyroglobulin Antibodies) 
What it does: Another autoimmune marker.
 High Anti-TG = Immune system reacting to your thyroid

7. Total T3 / Total T4
These measure all thyroid hormone (free + bound). Less specific than free T3/T4 but still helpful in some cases.

BONUS: Other helpful labs to check with your thyroid 
 Vitamin D – supports immunity & thyroid function
 Iron / Ferritin – needed to activate thyroid hormone
 B12 and Folate – for energy, mood & nervous system
 Cortisol – high stress can impact your thyroid

STILL FEELING BAD BUT LABS ARE “NORMAL”? 
Many people have “normal” results but still experience:
• Fatigue 
• Weight gain 
• Hair loss 
• Brain fog 
• Cold hands/feet 

This might mean your levels are “in range” but not optimal for you.

THYROID LAB SUMMARY TABLE 

Test – What It Tells You – High – Low
TSH – Brain’s signal to thyroid – Hypothyroid  – Hyperthyroid 
Free T4 – Main hormone produced – Hyperthyroid  – Hypothyroid 
Free T3 – Active hormone for energy – Hyperactive  – Low conversion 
Reverse T3 – Brake hormone (stress-related) – Blocked energy  – —
Anti-TPO / Anti-TG – Autoimmunity markers – Hashimoto’s / Graves’  – —

FINAL THOUGHTS 
Your thyroid is sensitive to:
• Stress 
• Gut health 
• Nutrients 
• Inflammation 

 Don’t rely on TSH alone. Always look at the full thyroid panel and how you feel.
 Work with someone who listens to your symptoms, not just your labs. 

Now this is just information for you, always talk to a Doc. about this. 

Danniela
IronSunshine ☀️

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