The Anti-Thyroglobulin (Anti-Tg) test checks for antibodies against thyroglobulin, a thyroid protein, indicating autoimmune thyroid issues (Hashimoto’s/Graves’) or thyroid cancer monitoring, while the TSH test (Thyroid-Stimulating Hormone) measures pituitary function to see if your thyroid is under/overactive; they’re often used together (with T3/T4) to get a full picture of thyroid health, diagnosing disorders, checking hormone levels, and monitoring cancer treatment effectiveness