Since you were tested for TPO ab, there must have been some question about you possibly being hypothyroid. If you would like us to try and assess your situation, please tell us about any symptoms you have. Also, please post any other thyroid test results such as Free T4, Free T3 and TSH, along with their reference ranges shown on the lab report. .
Under 9 IU/ml is normal. Your result of 1 IU/ml is within normal range. If you suspect you have Hashimoto's thyroiditis, also test thyroglobulin antibodies (TgAb). A small percentage with Hashimoto's thyroiditis have both antibodies within normal range; other tests would need to be done to confirm this autoimmune disease.