Hypothyroidism, a condition where the thyroid gland doesn't produce enough hormones, can lead to a wide range of symptoms. AACE President, Susan L. Samson, MD, PhD, FRCPC, FACE, explains the importance of a thorough diagnostic evaluation when assessing for hypothyroidism, as its symptoms often overlap with other conditions. Diagnosis typically involves blood tests to measure your thyroid-stimulating hormone (TSH) and T4 levels. Dr. Samson advises discontinuing biotin supplements before testing as it can interfere with test results, and cautions against using over-the-counter thyroid supplements, especially if your bloodwork is normal.