Hypothyroidism is a condition in which the body lacks sufficient thyroid hormone (too little thyroid activity).
Common causes include:
Autoimmune thyroiditis/Hashimoto's thyroiditis is an inflammation of the thyroid gland which leaves thyroid cells damaged or dead and incapable of producing sufficient hormones
Medical treatments: thyroid surgery to remove nodules or remove cancer and radioactive iodine may not leave enough hormone to meet the body's demand
Normal thyroid that does not produce enough hormones because of a problem with the pituitary gland
