Thyroid surgery:

Thyroid surgery is performed for a variety of reasons. A nodule or lobe of the thyroid is sometimes removed for biopsy or for the presence of an separately functioning adenoma causing hyperthyroidism. A large greater part of the thyroid may be removed, a subtotal thyroidectomy, to treat the hyperthyroidism of Graves' disease, or to remove a goitre that is unsightly or impinges on vital structures. A whole thyroidectomy of the entire thyroid, including associated lymph nodes, is the preferred treatment for thyroid cancer.

Taking away of the bulk of the thyroid gland usually produces hypothyroidism, unless the person takes thyroid hormone substitution. If the thyroid gland must be removed surgically, care must be taken to avoid harm to adjacent structures, the parathyroid glands and the recurrent laryngeal nerve. Both are susceptible to accidental removal and/or injury during thyroid surgery. The parathyroid glands produce parathyroid hormone (PTH), a hormone needed to maintain adequate amounts of calcium in the blood. Removal results in hypoparathyroidism and a need for supplemental calcium and vitamin D each day.