The Thyroid Peroxidase Antibodies test measures the presence of antibodies against thyroid peroxidase, an enzyme essential for thyroid hormone production. High levels of these antibodies may indicate autoimmune thyroid conditions, such as Hashimoto's thyroiditis, where the immune system mistakenly attacks thyroid tissue. This test is vital for diagnosing and monitoring autoimmune thyroid disorders, which can lead to symptoms like fatigue, weight gain, and sensitivity to cold. Understanding your antibody levels can help you and your healthcare provider determine the best course of action for managing your thyroid health.