Thyroid
What is TSH?
the signal that tells your thyroid what to do
- Unit
- mIE/L
- Sample
- Serum
- Fasting
- No fasting needed
- Turnaround
- 2 days
TSH is the signal from the pituitary to the thyroid. It is the most sensitive measure of thyroid function and changes early in both underactive and overactive states.
The pituitary releases TSH when thyroid hormones are low and suppresses it when they are high. The value therefore moves opposite to thyroid activity - high TSH means underactive thyroid, low TSH means overactive.
What does low TSH mean?
Low TSH usually means an overactive thyroid (hyperthyroidism). Symptoms can include palpitations, weight loss, heat intolerance, anxiety, and sweating.
What does high TSH mean?
High TSH suggests an underactive thyroid (hypothyroidism). Symptoms can include fatigue, weight gain, feeling cold, depression, and dry skin.
Panels that measure TSH
- Thyroid Test Base
- Fertility Test Base
- Health Check Base
- Menopause Test
- Stress Test Base
- Performance Test Plus
- Health Check Plus
- Female Hormone Test Plus
- Stress Test Plus
- Thyroid Test Plus
- Fertility Test Plus
- Thyroid Test Complete
- Performance Test Complete
- Fertility Test Complete
- Female Hormone Test Complete
- Stress Test Complete
- Health Check Complete
- Health Check Man
- Health Check Kvinna
Reading
- Tired all the time? The blood values that can explain why
- The menstrual cycle phase by phase: what your hormones do
- Trying for a baby: the blood tests worth taking first
- PCOS and blood tests: the values that bring clarity
- Men's health after 40: values worth following every year
- Normal TSH but still tired: what could be behind it?
- What is included in a blood test health check?
- Menopause or your thyroid: the symptoms that overlap and the blood tests that tell them apart
- Blood tests without a referral: how it works in Sweden
- How we work with reference intervals
More markers in the same area
Launching in Stockholm in 2026.
Want to know when you can order?
This is general information about the marker, not an assessment of your values and not medical advice. Last updated: August 2026.