Testing your hormones starts with a simple TSH blood test.

Your thyroid is essential to your overall health and wellbeing. Thyroid hormones influence everything from your heart rate to how quickly your body burns calories. They can also influence factors as subtle as your mood or as vital as your fertility.

This TSH blood test measures thyroid stimulating hormone (TSH), which stimulates the thyroid to produce two additional hormones, T4 (thyroxine) and T3 (triiodothyronine), both of which play a critical role in controlling the body’s metabolism. Typically, low or high TSH levels indicate potential problems related to the function of your thyroid.