Thyroid Stimulating Hormone (TSH) Test

A TSH test is used to check the level of thyroid-stimulating hormone in the blood. Your TSH level can indicate if your thyroid gland is working properly.

While a TSH test is usually used as the initial blood test to detect hypothyroidism, the doctor may need to order additional tests to diagnose hypothyroidism. The doctor also may check your level of FT₄, or free thyroxine, which is the amount of thyroxine in your body.

It’s important to know that blood tests are not the only way the doctor determines your hypothyroidism diagnosis. Asking how you’re feeling is just as important. Reviewing your TSH results and discussing all your symptoms helps the doctor see the bigger picture.