Thyroid

TSH

Thyroid-Stimulating Hormone. Measured in clinic at The Wellness in Marylebone, read by a doctor.

What It Is

Thyroid-stimulating hormone is made by the pituitary gland at the base of the brain, and it tells the thyroid how much hormone to produce. Because the pituitary responds sensitively to thyroid hormone levels, TSH acts as an early readout of how the thyroid is performing.

Why It Matters

Thyroid hormones set the pace of metabolism, influencing energy, weight, temperature regulation, mood and heart rate. TSH is the standard first-line test when a thyroid problem is suspected, and small shifts can appear before symptoms are obvious.

What Results Can Suggest

A high TSH can suggest the thyroid is underactive and the pituitary is working harder to drive it. A low TSH can suggest the thyroid is overactive. Either pattern usually prompts further thyroid hormone tests rather than a conclusion on its own, so discuss your result with a doctor.

This page is general information, not medical advice and not a substitute for a consultation. Reference ranges vary between laboratories, and results should always be interpreted by a doctor who knows your history.