This test measures thyroglobulin antibody, also known as antithyroglobulin antibody (ATA) and is often used in conjunction with the thyroid peroxidase antibody (TPO). Doctors often use these tests to help them assess thyroid function, follow treatment for thyroid disease and differentiate between autoimmune conditions of the thyroid. Antibodies to thyroglobulin can result in symptoms of low thyroid such as fatigue, weight gain, dry skin and constipation. Conditions such as Hashimoto’s thyroiditis, lupus, rheumatoid arthritis, and pernicious anemia often have these antibodies present. Fasting is not required for this test. Take all medications as prescribed.