What Are the Causes of Hypothyroid?

The thyroid is located below the larynx at the front of the neck. This gland controls hormones that are linked to metabolism. Hypothyroidism results when the thyroid gland creates an insufficient amount of thyroid hormone. This results in a slower pace for the overall systems in the body. Women have a higher rate of hypothyroidism than men, notes the National Endocrine and Metabolic Diseases Information Service. This disorder is often treated via administration of thyroid hormone in a pill.

Inflammation of Thyroid

Hashimoto’s disease (chronic lymphocytic thyroiditis), is the most frequent cause of hypothyroidism in America. In this disorder the thyroid is attacked by antibodies produced by the immune system.


Radiation to the neck for cancer is a cause of hypothyroidism. Radiation damages cells in the thyroid and hinders its function. Radiation often causes permanent malfunction of the thyroid.


The use of certain drugs in medical treatments also causes hypothyroidism. Some drugs that may cause hypothyroidism include amiodarone, interleukin-2, propylthiouracil, methimazole, lithium and interferon alpha.

Salt Levels

An improper balance of iodine (salt) in the body is a cause of hypothyroidism, notes Thyroid.org. Salt is crucial to regulate the creation of the thyroid hormone. High or low levels of iodine often wreak havoc with the function of the thyroid.

Congenital Defect

Hypothyroidism is sometimes a congenital defect that is present at birth. Sometimes when a baby is born, the thyroid does not work properly or is not completely developed. This birth defect will require treatment to ensure the baby develops full cognitive function.


Thyroiditis is a cause of hypothyroidism. This disorder occurs when thyroid hormone drips out of an irritated thyroid. This first causes hyperthyroidism and then hypothyroidism. Also, in postpartum thyroiditis, a pregnancy can result in the development of hypothyroidism, notes MedlinePlus.

Radioactive Iodine Treatment

Another cause of hypothyroidism is treatment with radioactive iodine for hyperthyroidism. This treatment can result in permanent hypothyroidism.

Surgical Removal of Thyroid

A myriad of diseases also cause hypothyroidism. Certain medical problems require surgical removal of the entire thyroid. These disorders include thyroid cancer, a goiter and thyroid nodules.

Sheehan Syndrome

Another disease that causes hypothyroidism is Sheehan syndrome. This disease causes permanent destruction of the pituitary gland.

About this Author

Julia Bodeeb worked on staff in medical book/journal publishing for over a decade as a reporter, managing editor, and book acquisitions. She is now a writer at LIVESTRONG, Bright Hub, Associated Content, and Seed. Ms. Bodeeb has a B.A. in English and postgraduate credits in psychology and law. She won a Pulitzer Center Global Issues/Citizen Voices Award in 2008.