What are the Causes of Hypothyroidism?
Severe iodine deficiency is the main cause of hypothyroidism. However, other conditions or procedures may also cause the disorder. Some of them are:
- Hashimoto's thyroiditis - The most common cause of hypothyroidism is an inherited condition called Hashimoto's thyroiditis. This condition is named after Dr. Hakaru Hashimoto who first described it in 1912. In this condition, the thyroid gland is usually enlarged (goiter) and has a decreased ability to make thyroid hormones. Hashimoto’s is an autoimmune disease in which the body’s immune system inappropriately attacks the thyroid tissue.
- Lymphocytic thyroiditis following hyperthyroidism - Thyroiditis refers to inflammation of the thyroid gland. When the inflammation is caused by a particular type of white blood cell known as a lymphocyte, the condition is referred to as lymphocytic thyroiditis. This condition is particularly common after pregnancy.
- Thyroid destruction from radioactive iodine or surgery.
- Partial surgical removal of the thyroid gland can also be the cause of this disorder since the total mass of thyroid producing cells left within the body are not enough to meet the needs of the body.
- Pituitary or hypothalamic disease.
- Medications that are used to treat an over-active thyroid (hyperthyroidism) may actually cause hypothyroidism. The psychiatric medication, lithium, is also known to alter thyroid function and cause hypothyroidism.