What is Thyroid-Stimulating Hormone?

Thyroid-stimulating hormone (TSH) is produced by your pituitary gland following the secretion of thyrotropin-releasing hormone (TRH) by a part of the brain called the hypothalamus. Once released into the bloodstream TSH is responsible for stimulating the thyroid gland to produce hormones T4 (thyroxine) and T3 (triiodothyronine). T4 is inactive and is thus converted to the active T3 form mainly in the liver, but also in the kidneys, brain, and other organs. In a negative feedback mechanism, circulating T3 inhibits both TRH and TSH release. A change in your TSH level can be an early sign of a thyroid problem.




Why is it included in the Balance Axis?

Tracking your TSH levels allows you to understand the health of your thyroid gland, which is an integral part of your endocrine system. The thyroid gland's chief function is to regulate metabolism but also plays an important role in maintaining normal growth and development, body temperature, and energy levels. Because of its significance, TSH is included in SiPhox Health's base panel. The Thyroid+ panel includes T4, T3, and thyroid peroxidase (TPO) in addition to the base panel for individuals seeking a more comprehensive thyroid test.

How can I better understand my results?

According to UCLA Health, normal levels of TSH are around 0.5-5.0 uIU/mL, although for those who are pregnant, have a history of thyroid cancer and/or pituitary gland disease, or are older, the normal range may be different. If you are concerned with your levels, it is important to consult with your physician.

High TSH may point to hypothyroidism (underactive thyroid gland) whereas low TSH may point to hyperthyroidism (overactive thyroid gland). Symptoms of hypothyroidism include lethargy, weight gain, sensitivity to cold, thinning hair, constipation, and other physical and mental issues. Symptoms of hyperthyroidism on the other hand include weight loss, rapid or irregular heartbeat, increased hunger, and anxiousness among other issues. There are a variety of other conditions that abnormal TSH levels may indicate, including Graves' disease or Hashimoto's disease to name a few.

Like many hormones, TSH follows a circadian rhythm with maximal concentrations overnight and minimal in the evening. As such, testing TSH in the morning compared to in the afternoon may help detect hypothyroidism in individuals who would otherwise appear normal due to rhythmic fluctuation.

If your TSH levels are high, you can try:

If your TSH levels are low, you can try:

Where can I learn more?

Cleveland Clinic - TSH

Alila Medical Media (Video) - Thyroid Gland, Hormones and Thyroid Problems

EndocrineSurgeon.co.uk - What does the Thyroid Gland do?