what blood test is done for hypothyroidism
TESTS. Blood tests to measure TSH, T4, T3 and Free T4 are readily available and widely used. Tests to evaluate thyroid function include the following: TSH TESTS The best way to initially test thyroid function is to measure the TSH level in a blood sample.A high TSH level indicates that the thyroid gland is failing because of a problem that is directly affecting the thyroid (primary hypothyroidism).ests to evaluate thyroid function include the following: TSH TESTS The best way to initially test thyroid function is to measure the TSH level in a blood sample. A high TSH level indicates that the thyroid gland is failing because of a problem that is directly affecting the thyroid (primary hypothyroidism).