Hypothyroidism has several causes, including
- Hashimoto’s (autoimmune) disease
- Thyroiditis, or inflammation of the thyroid
- Congenital hypothyroidism, or hypothyroidism that is present at birth
- Surgical removal of part or all of the thyroid
- Radiation treatment of the thyroid
Less often, hypothyroidism is caused by too much or too little iodine in the diet or by pituitary disease.
What is Hashimoto’s disease?
Hashimoto’s disease is the most common cause of hypothyroidism. Hashimoto’s disease is an autoimmune disorder. With this disease, your immune system attacks the thyroid. The thyroid becomes inflamed and can’t make enough thyroid hormones.