Clinician handoff
Thyroid
Designed for a 60-second scan in primary care. Use this to explain why this theory fits, what would weaken it, and which tests are most worth discussing.
Why this still fits
I've been experiencing persistent brain fog and fatigue for [DURATION]. I'd like to investigate thyroid contributors with a complete panel rather than relying on TSH alone, especially because the symptom pattern still looks thyroid-like.
What would weaken it
- -No slowed-body story, no cold intolerance, no constipation, no skin or hair changes, and no thyroid lab support.
- -Thyroid testing is clean and the symptoms fit depression, sleep apnea, menopause, or another overlap better.
- -The fog is strongly positional or meal-linked in ways thyroid disease usually isn't.
Key points to communicate
- •I want a full thyroid picture, not a one-number dismissal.
- •Please separate thyroid-related slowing from depression, menopause transition, anemia, and sleep problems.
- •If thyroid isn't the answer, I want to know which nearby causes still fit the same symptom cluster.
Bring this to the visit
- •Recent thyroid labs: TSH, Free T4, Free T3, and TPO antibodies with dates.
- •A timeline of symptoms relative to thyroid diagnosis or medication changes.
- •Current thyroid medication: type (T4-only vs combination), dose, and when you take it.
- •A list of co-occurring symptoms: cold intolerance, weight changes, hair loss, constipation.
Useful screening structure
- -Full thyroid panel (TSH, Free T4, Free T3, TPO antibodies) - not TSH alone.
- -Iron panel and vitamin D since both are commonly deficient alongside thyroid disease.
- -Celiac panel if Hashimoto's is diagnosed - celiac co-occurs in 2-5% of cases.
Tests and measurements to discuss
TSH
What this helps clarify: Primary thyroid screening marker.
Range context
1.0–2.0 mIU/L (optimal)
How to use the result
Save the result with date and symptoms from the same week.
Free T3
What this helps clarify: Active thyroid hormone that directly affects brain function
Range context
3.0–4.0 pg/mL
How to use the result
Save the result with date and symptoms from the same week.
Free T4
What this helps clarify: Thyroid hormone precursor - low levels indicate hypothyroidism
Range context
1.0–1.5 ng/dL
How to use the result
Save the result with date and symptoms from the same week.
TPO Antibodies
What this helps clarify: Elevated in Hashimoto's thyroiditis - autoimmune thyroid attack
Range context
<35 IU/mL
How to use the result
Save the result with date and symptoms from the same week.
TG Antibodies
Ferritin
What this helps clarify: Iron storage marker that can affect energy, focus, and cognition.
Range context
40-100 ng/mL
How to use the result
Save the result with date and symptoms from the same week.
Vitamin B12
What this helps clarify: Patient-facing vitamin B12 explainer route, useful when a story or clinician uses plain language instead of the active-B12 variant.
Range context
Lab context
How to use the result
Save the result with date and symptoms from the same week.
25-OH Vitamin D
What this helps clarify: Severe deficiency doubles dementia risk
Range context
40–60 ng/mL
How to use the result
Save the result with date and symptoms from the same week.
Reverse T3 (not routine - only discuss if a specialist thinks the broader picture justifies it)
What this helps clarify: Inactive T3 form - elevated during illness, stress, or low-calorie states
Range context
10–24 ng/dL
How to use the result
Save the result with date and symptoms from the same week.
Questions to ask directly
- •My TSH is 'normal' but I still feel foggy - should we look at Free T3 and antibodies?
- •If I have Hashimoto's, should we check for iron, B12, vitamin D, and celiac deficiency?
- •Would adding T3 medication help if T4-only levothyroxine isn't resolving the fog?
- •Is my TSH target optimal for symptoms (many feel best at TSH 0.5-2.0, not just 'in range')?
Functional impact snapshot
- -Rate fog severity before and after thyroid medication dose adjustments.
- -Track whether cognitive function improves over the expected 4-8 week period on treatment.
- -Note if fog correlates with other thyroid symptoms (fatigue, cold intolerance) or moves independently.
Escalate instead of self-managing if
- •Myxedema signs: severe hypothermia, altered consciousness, bradycardia - emergency.
- •Thyroid storm: high fever, rapid heart rate, agitation, confusion - emergency.
- •Rapidly enlarging thyroid nodule or compressive symptoms.
Peer-reviewed references
- 1. Jonklaas et al., Thyroid, 2014 - ATA Hypothyroidism Guidelines [DOI]
- 2. Pearce SH et al., Eur Thyroid J, 2013 - ETA Guideline: Management of Subclinical Hypothyroidism [DOI]
- 3. 10.1089/THY.2016.0457 [DOI]
- 4. ETTLESON ET AL. 2022; NICE NG145; SAMUELS & BERNSTEIN 2022 [DOI]
- 5. SAMUELS & BERNSTEIN 2022; WIERSINGA 2014 [DOI]