That depends on your symptoms. If you are experiencing a change in energy level, change in body weight, rapid heart rate, palpitations, or excessive sweating, you should return to your doctor for further evaluation. Otherwise, it seems as if your doctor has diagnosed you with “subclinical thyrotoxicosis” which means that you have a low TSH with normal T3 and T4 thyroid hormone levels. There are a number of causes but patients who have normal physical exams and no symptoms are usually re-evaluated in a few weeks as the hormones usually normalize without treatment.