What is hyperthyroidism and hypothyroidism?
Hypothyroidism means there is not enough thyroid hormone in one’s system. Hyperthyroidism is just the opposite; it means that there is too much. Hashimoto’s disease may cause the thyroid gland to become underactive or enlarged over time. Treatments for hyperthyroidism with radioactive iodine, radiation therapy for head and neck cancers, and thyroid surgery, as well as certain medications can also cause hypothyroidism. Grave’s disease is the common cause of hyperthyroidism, though it may also be caused by thyroid nodules and thyroid inflammation.
