Thyroid Panel with TSH - a test that measures the amount of TSH(Thyroid Stimulating Hormone), produced by the pituitary gland, in the blood. A high TSH level indicates that the thyroid gland is failing because of a problem that is directly affecting the thyroid (primary hypothyroidism). The opposite situation, in which the TSH level is low, usually indicates that the person has an overactive thyroid that is producing too much thyroid hormone (hyperthyroidism). Occasionally, a low TSH may result from an abnormality in the pituitary gland, which prevents it from making enough TSH to stimulate the thyroid (secondary hypothyroidism). In most healthy individuals, a normal TSH value means that the thyroid is functioning normally. The levels of the Thyroxine or T4 and triiodothyronine or T3, the two hormones produced by the thyroid gland, are checked to tell if your thyroid is working properly.