Hormones . Symptoms guide
Thyroid Symptoms: When and What to Test
Quick answer
Thyroid disease is common and presents subtly. While standard UK clinical protocols use TSH as an initial gatekeeper, checking your full TSH, free T4 and free T3 profile simultaneously provides an immediate, comprehensive baseline. This avoids the logistical delay of multi-step laboratory reflex testing if your initial markers are borderline. The Hormone Specialist panel includes the full TSH / T3 / T4 thyroid screen. The Advanced Hair and Hormone Check adds TPO and thyroglobulin antibodies on top, which together identify underlying autoimmune thyroid activity (the primary driver behind Hashimoto thyroiditis and chronic follicular inflammation) in up to 95 percent of cases.
This patient information is being clinically reviewed by our team. The factual content draws on UK guidance (NHS, NICE, British Association of Dermatologists, and other specialist society guidance where cited).
What this might be
- Hypothyroidism. Tiredness, weight gain, cold intolerance, hair loss, low mood.
- Hyperthyroidism. Anxiety, weight loss, palpitations, heat intolerance.
- Subclinical thyroid disease. TSH outside range, T3 and T4 normal. Often best detected with the full panel.
- Hashimoto thyroiditis. Autoimmune; TPO and thyroglobulin antibodies are included in the Advanced Hair and Hormone Check.
Common features that suggest this
- Persistent fatigue not explained by sleep
- Unexplained weight change
- Hair thinning or shedding
- Cold or heat intolerance
- Anxiety, palpitations, or tremor
- Constipation or loose stools
Recommended tests
Same-day appointments at our Harley Street clinic, results clinician-reviewed.
Need a marker not in these panels? Build a custom panel and a GMC-registered clinician will design one for you.
Markers your clinician will commonly look at
These are the individual blood markers in the recommended panels above. Click any to read what it measures, its UK reference range, and what high or low values mean.
Testing advice
No fasting required. Morning sample is preferable. If you take levothyroxine, take it after the blood draw rather than before.
Common questions
Why test free T3 and T4 if my TSH is normal?
TSH alone is the appropriate first-line screen recommended by UK guidance (NICE CKS, British Thyroid Association) and is sufficient for the vast majority of cases. Adding free T4 and free T3 in the same draw is useful where symptoms persist despite a borderline or normal TSH, or in the rare scenario of central (pituitary-driven) hypothyroidism where TSH alone would mislead. Doing all three at once also avoids the back-and-forth of reflex testing if your initial TSH comes back borderline.
Do you test thyroid antibodies?
Yes. Both <a href="/biomarkers/tpo-antibodies/">TPO antibodies</a> and <a href="/biomarkers/thyroglobulin-antibodies/">thyroglobulin antibodies</a> are part of our <a href="/panels/advanced-hair-and-hormone-check/">Advanced Hair & Hormone Check</a>. The two complement each other: TPO comes back positive in around 95 percent of Hashimoto cases (and a smaller proportion of Graves disease), while thyroglobulin antibodies pick up a further 5 to 10 percent of autoimmune cases where TPO is negative. Testing both gives the clearest picture in one appointment.
Related symptoms
Sources and further reading
- NICE CKS: Hypothyroidism
- British Thyroid Association (BTA): UK guidelines for the use of thyroid function tests
- Society for Endocrinology (SfE)
This page provides general information only and is not a substitute for medical advice. A GMC-registered clinician will review your results and tailor any recommendations to you personally.