Aid clinicians in obtaining an appropriate diagnosis for common adult thyroid disorders. The cascade begins with a third-generation thyroid-stimulating hormone (TSH) test. If the TSH result is normal.a euthyroid status is assumed and testing stops. Additional testing is only performed if the initial TSH result is abnormally high or low. The cascade algorithm will select specific tests, based on the results of previously performed tests.which are necessary to arrive at the most appropriate laboratory diagnosis. The assayed value of a test, relative to the reference interval of that specific test.determines which.if any.additional tests are performed. The cascade proceeds.selecting specific tests.until the most probable diagnosis can be made. The thyroid panel test includes the following: Thyroid Stimulating Hormone (TSH).Free thyroxine index (FTI), thyroxine (T4), and thyroid hormone binding ratio (T3 uptake).