The thyroid gland is responsible for regulating the body's metabolism, which includes the rate at which cells use energy.

The thyroid gland produces two main hormones: Thyroxine (T4) and Triiodothyronine (T3). These hormones regulate metabolism, growth, and development.

Iodine is an essential component of thyroid hormones. It is incorporated into the structure of T4 and T3.

Weight gain is a common symptom of hypothyroidism, which is a condition where the thyroid gland does not produce enough thyroid hormones.

Fatigue is a common symptom of hyperthyroidism, which is a condition where the thyroid gland produces too much thyroid hormones.

Hashimoto's thyroiditis is the most common cause of hypothyroidism. It is an autoimmune disorder where the body's immune system attacks the thyroid gland.

Graves' disease is the most common cause of hyperthyroidism. It is an autoimmune disorder where the body's immune system produces antibodies that stimulate the thyroid gland to produce too much thyroid hormones.

Hypothyroidism is treated with thyroid hormone replacement therapy, which involves taking synthetic thyroid hormones to replace the hormones that the thyroid gland is not producing.

Hyperthyroidism is initially treated with antithyroid medications, which block the production of thyroid hormones. Radioactive iodine therapy or surgery may be used if antithyroid medications are not effective.

The thyroid gland plays a crucial role in fetal development, particularly in the development of the brain. It produces hormones that are essential for the proper growth and maturation of the fetal brain.

Goiter is a condition characterized by an enlarged thyroid gland. It can be caused by various factors, including iodine deficiency, autoimmune disorders, and thyroid nodules.

Papillary thyroid cancer is the most common type of thyroid cancer. It is characterized by the presence of papillary structures in the thyroid tissue.

Family history of thyroid cancer is a risk factor for developing the disease. Individuals with a family history of thyroid cancer have an increased risk of developing the disease themselves.

Surgery is the primary treatment for thyroid cancer. The extent of surgery depends on the stage and type of thyroid cancer.