TSH: what it is, values and what high or low means
A hormone made by the pituitary gland. It tells the thyroid how much T4 and T3 to release. TSH reacts to small changes in thyroid hormone, so it is usually the first thyroid test. A high TSH often points to a slow thyroid; a low TSH to an overactive one.
Values
Ranges vary by method. No optimal band is shown — none narrower than the lab’s is widely agreed.
| Type | Value | Units | Laboratory | Sex | Age |
|---|---|---|---|---|---|
| Value awaiting review | 0.4–4.0 | µIU/mL | Not specified | Not specified | adults |
These values come from content awaiting review. The laboratory is unspecified and their classification as intervals, thresholds or targets has not been verified. Discuss the interval on your report with your doctor.
High and low
A high TSH often points to a slow thyroid. consult your doctor
A low TSH often points to an overactive thyroid. consult your doctor
What affects the result
- Time of day, illness, pregnancy and some medicines. Biotin supplements can interfere with the test itself, so tell us if you take them.
How we measure it
Not currently available in our profiles
Included in
Complete Thyroid Profile
TSH, Free T4, Free T3 See all
Confirm the preparation before your visit.
€225
Not included: Does not include anti-TPO, anti-Tg or TRAb. It does not assess thyroid autoimmunity.
Basic Female Hormone Profile
Estradiol, Progesterone, FSH See all
Confirm the preparation before your visit.
€255
Not included: Does not include AMH, SHBG, DHEA-S, cortisol, insulin or β-hCG. It does not cover ovarian reserve or a fertility assessment.