What causes hypothyroidism?
Hypothyroidism has several causes, including • Hashimoto’s disease • thyroiditis, or inflammation of the thyroid gland • congenital hypothyroidism, or hypothyroidism that is present at birth • surgical removal of part or all of the thyroid gland • radiation treatment of the thyroid • some medications Less commonly, hypothyroidism is caused by too much or too little iodine in the diet or by abnormalities of the pituitary gland.