The TSH blood test measures Thyroid Stimulating Hormone, the key regulator of thyroid function. TSH is produced by the pituitary gland in response to signals from the hypothalamus and plays a central role in controlling how much thyroid hormone your body makes. Because of this feedback system, TSH is often the first and most sensitive indicator of thyroid imbalance. TSH works by signaling the thyroid gland to produce thyroxine, T4, which is then converted into triiodothyronine, T3, the active hormone that regulates metabolism. These hormones influence nearly every tissue in the body, affecting heart rate, body temperature, mood, energy levels, digestion, and cognitive function. When thyroid hormone levels shift, TSH adjusts accordingly in an effort to restore balance. If thyroid hormone levels are too low, the pituitary releases more TSH to stimulate the thyroid. If thyroid hormone levels are too high, TSH production decreases. Elevated TSH levels typically suggest hypothyroidism, or an underactive thyroid. Low TSH levels often indicate hyperthyroidism, or an overactive thyroid. Measuring TSH provides a clear starting point for evaluating thyroid health. Thyroid disorders are common and can develop gradually, often mimicking other conditions. Early detection through TSH testing allows for timely intervention, improved symptom management, and prevention of long-term complications. This simple blood test delivers powerful insight into overall endocrine health. What Is Included In This Test? This test includes: Measurement of Thyroid Stimulating Hormone levels in the bloodClear numerical results for clinical interpretationThis test measures TSH only and does not include T3 or T4. Why Does This Test Matter? TSH is widely considered the most reliable initial screening test for thyroid dysfunction. Even small changes in thyroid hormone levels can cause significant shifts in TSH, making it an early indicator of imbalance. High TSH levels may indicate hypothyroidism, which can cause weight gain, fatigue, dry skin, depression, constipation, heavy menstrual cycles, and high cholesterol. The most common cause of hypothyroidism is Hashimoto thyroiditis, an autoimmune condition. Low TSH levels may indicate hyperthyroidism, which can lead to weight loss, rapid heartbeat, heat intolerance, anxiety, tremors, and sleep disturbances. Early identification reduces the risk of complications such as heart rhythm disorders or bone loss. Because TSH alone cannot determine the exact cause of thyroid dysfunction, abnormal results are often followed by additional thyroid hormone testing for a complete evaluation. Who Should Consider This Test? You may consider this test if you: Experience unexplained weight gain or weight lossHave persistent fatigue or low energyFeel unusually anxious or depressedHave hair thinning or dry skinExperience cold or heat intoleranceHave irregular or heavy menstrual cyclesHave difficulty sleepingHave a family history of thyroid diseaseRecently gave birthAre entering menopause Convenient, No-Appointment Testing To complete your test: Order online through our website Use the lab locator to find a nearby testing location Walk in; no appointment required Access your results securely in your HealthLabs.com account within one to three business days 110% Price Guarantee! If you find the same test for a lower price from a comparable provider, contact us. We not only match the price, we beat it by an additional 10 percent of the difference.