My recent test results show a low TSH, normal T4, & high T3 levels. My indocrinologist prescribed another test (involving use of radioactive iodine, scan procedures, etc.) which i think is meant to find out the functionality or condition of my thyroid. That was 2 weeks ago yet, & i did not yet submit to the test procedures because of the expense. Do i really need that test? I feel i am improving now in so far as the symptoms are concern.