Hypothyroidism Causes

• Loss of thyroid tissue: Treatment of hyperthyroidism by radioactive destruction of thyroid tissue or surgical removal of thyroid tissue can result in hypothyroidism.
  
• Antithyroid antibodies: These may be present in people who have diabetes, lupus, rheumatoid arthritis, chronic hepatitis, or Sjogren's syndrome. These antibodies may cause decreased production of thyroid hormones.
  
• Congenital: Hypothyroidism can be present from birth. This is commonly discovered early with nationwide newborn screening for this disease.
  
• Defects in the production of thyroid hormone: Hashimoto's thyroiditis occurs when there are defects in the production of thyroid hormone, resulting in an increased amount of TSH. The increased TSH results in a goiter (enlargement of the thyroid gland itself that can be seen as an obvious swelling in the front of the neck).
  
• Medications: Some medications, particularly lithium (Eskalith, Lithobid), may cause a drug-induced hypothyroidism.