Usually primary hypothyroidism is a condition in which the thyroid gland itself functions abnormally, resulting in hypothyroidism. The usual causes of primary hypothyroidism include the following: 1. Thyroid autoimmune reasons, autoimmune function abnormalities caused by various reasons, usually lead to the production of abnormal antibodies in the body, to a certain extent, destroying the function of the thyroid gland, which in turn leads to the body’s thyroid hormone deficiency, thus leading to hypothyroidism. 2. The relative insufficiency of thyroid hormone production by the remaining thyroid gland due to radioactive iodine treatment or surgical destruction can also lead to hypothyroidism. It is recommended that patients with primary hypothyroidism need to consult an endocrinologist for treatment.