There are a few causes of hypothyroidism. The most common cause of hypothyroidism is Autoimmune thyroid disease.
Other causes include:
Type
Underlying causative factor
Autoimmune
Atrophic autoimmune thyroiditis, Hashimoto’s thyroiditis
Iodine deficiency
Poor intake of dietary iodine
Iatrogenic
Radioiodine therapy, Removal of thyroid glands
Medication side-effect
Amiodarone, Interferon, Rifampicin, Lithium, Methimazole, Propylthiouracil, Thalidomide, Sunitinib…