Thyroid Stimulating Hormone (TSH)

Overview:

TSH is released by the pituitary gland and instructs the thyroid to produce hormone. The relationship is inverse: when thyroid hormone is low, the pituitary produces more TSH to compensate, and when thyroid hormone is high, TSH falls. Because the pituitary is very sensitive to small changes, TSH often moves before the thyroid hormones themselves leave the normal range, which is why it is generally the first test used. An abnormal TSH is usually followed by free T4, and sometimes free T3, to establish what is happening. Illness, pregnancy and some medications affect the result.

Categories:

Thyroid

Biomarkers:

1 biomarker