Thyroid, explained
TSH, free T4, free T3 and thyroid antibodies. The TSH range changes with age — we use the range for yours.
Three things we do that a printed range doesn’t
Ranges change with both. We use the set for you — 26 range sets in total.
TSH is read with free T4 and antibodies; one high TSH is often temporary.
ETA (European Thyroid Association). Organisation, document, year.
TSH — the ranges we use
ETA: the main thyroid screening test; an abnormal result indicates an under-/overactive thyroid (energy, weight, mood).
| Rating | Range | What it means |
|---|---|---|
| Worth improving | below 0.4 mIU/L | Low TSH — possible overactive thyroid; seek advice. |
| Good | 0.4 – 4 mIU/L | TSH within the reference range. |
| Worth improving | 4 – 10 mIU/L | Slightly elevated (subclinical) — monitor fT4/antibodies. |
| Talk to a doctor | 10 mIU/L and above | Elevated — possible underactive thyroid; seek advice. |
This marker also has 4 age- or sex-specific range sets in the app — the table shows the general one.
Articles in this guide
- Thyroid: which tests tell you what, and how to do them properlyMarker explained
- Hashimoto's: what it is, what is proven to help and what the latest research saysMarker explained
- TSH: normal values, what a high TSH means and when it is a diseaseThyroid
- AI blood test analyzer: what it can and cannot do (and how to use ChatGPT safely)Reading your report
- Blood test reference values — table by test for adultsReading your report
- Blood tests before pregnancy: what to check before you conceiveLife stages
- ChatGPT prompt for blood test results: a safe template and what to checkReading your report
- Fatigue: which blood tests explain it — and which don'tSymptom → test
This content is for information only and is not a substitute for medical advice. Talk to your doctor about your results.
Good to know
Is TSH 4.6 high?
Upload your report and you’ll see the answer for your exact value, age and sex — with the source of the range. In general: one value outside the printed range is rarely an emergency; the pattern and the trend matter more.
Do I need a new test?
No. Upload the one you already have. If a re-test is useful, the plan tells you when.
Is this a diagnosis?
No. It is an explanation to help you and your doctor. When a value needs a doctor, we say so.