Thyroid-Stimulating Hormone (TSH) Unit Converter

Thyroid-stimulating hormone (TSH), also called thyrotropin, is a hormone produced by the pituitary gland at the base of your brain. It signals your thyroid gland to produce and release thyroid hormones, specifically thyroxine (T4) and triiodothyronine (T3).

TSH works through a feedback loop with your thyroid. When thyroid hormone levels drop, your pituitary releases more TSH to stimulate the thyroid. When thyroid hormone levels rise, TSH production decreases. This makes TSH the most sensitive marker of thyroid function.

High TSH typically indicates an underactive thyroid (hypothyroidism), while low TSH usually suggests an overactive thyroid (hyperthyroidism). The normal reference range is generally 0.4-4.0 mIU/L, though this can vary by age and laboratory.

TSH is produced by the anterior pituitary gland in response to thyrotropin-releasing hormone (TRH) from the hypothalamus. The pituitary gland is located at the base of the brain and acts as the master regulator of thyroid function.