It’s estimated that around 6% of women and 4% of men have an undiagnosed thyroid problem – most commonly an underactive thyroid gland.
Thyroid Stimulating Hormone (TSH)
TSH is a pituitary hormone which stimulates your thyroid gland to secrete thyroxine and triiodothyronine.
T4 plays a role in growth and metabolism in your body. This test measures your free T4 (FT4) levels, as free T4 looks at only what is active and available for your body to use.