Thyroid cancer is a type of cancer that begins in the cells of the thyroid gland, which is located in the front of the neck and produces hormones that regulate metabolism. Thyroid cancer is relatively rare compared to other types of cancer, but its incidence has been increasing in recent years. There are several types of thyroid cancer, with the most common being papillary thyroid cancer, followed by follicular thyroid cancer, medullary thyroid cancer, and anaplastic thyroid cancer. Symptoms of thyroid cancer can include lumps or nodules in the thyroid gland, difficulty swallowing, hoarseness, or changes in voice. Treatment for thyroid cancer typically involves surgery to remove the tumor, followed by radioactive iodine therapy, hormone therapy, or external beam radiation therapy. The prognosis for thyroid cancer is generally good, with a high survival rate for most types of thyroid cancer when detected and treated early.