High thyroid antibodies are usually caused by autoimmune thyroid disease. There are two types of thyroid autoantibodies, thyroid peroxidase antibodies and thyroglobulin antibodies, and elevated autoantibodies are usually indicative of autoimmune thyroid disease, such as thyroiditis. Thyroiditis can cause elevated antibodies, and one of the most common is Hashimoto’s thyroiditis, or chronic lymphocytic thyroiditis, an autoimmune disease that can lead to diffuse goiter and can be accompanied by hyperthyroidism. If the thyroid antibodies are high but there are no clear clinical signs and symptoms, treatment is usually not needed. If the antibodies are elevated and accompanied by hypothyroidism or hyperthyroidism, symptomatic treatment is required as prescribed by the doctor.