Your thyroid stimulating hormone ( TSH ) level indicates how well your thyroid is functioning. Learn about targeted reference levels as you age and during pregnancy. A thyroid stimulating hormone ( TSH ) test measures the amount of TSH in the blood . A blood test can measure TSH and help a doctor diagnose a thyroid condition such as hypothyroidism or hyperthyroidism. TSH blood tests are routinely used to help adjust the dose of replacement thyroid medication in patients with hypothyroidism. TSH is also a test that is done to help the healthcare provider determine whether hypothyroidism might be the cause of symptoms like cold intolerance, fatigue, weight gain, and constipation. Learn how TSH levels reflect thyroid function and what factors can influence them. Find out the normal range, causes and effects of high or low TSH , and how to interpret your test results.
